Jiří Tuček

2011

• J. Cuda, T. Kohout, J. Tucek, J. Haloda, J. Filip, R. Prucek, and R. Zboril, “Low-temperature magnetic transition in troilite: A simple marker for
  highly stoichiometric FeS systems,” JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, vol. 116, 2011.
  [Bibtex]

  @article ISI:000297257000001,
  Author = Cuda, J. and Kohout, T. and Tucek, J. and Haloda, J. and Filip, J. and
     Prucek, R. and Zboril, R.,
  Title = Low-temperature magnetic transition in troilite: A simple marker for
     highly stoichiometric FeS systems,
  Journal = JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,
  Year = 2011,
  Volume = 116,
  Month = NOV 15,
  Abstract = Low-temperature magnetic evolution of troilite sample, extracted from
     the Cape York IIIA octahedrite meteorite, was investigated by employing
     macroscopic magnetic measurement, Mssbauer spectroscopy, scanning
     electron microscopy (SEM) and backscattered electrons (BSE) microscopy,
     X-ray diffraction (XRD), electron microprobe analysis (EMA), and atomic
     absorption spectrometry (AAS). The study identified a magnetic
     transition at approximate to 70 K manifested itself in a similar manner
     as previously reported for troilite from the Bruderheim L6 chondrite
     meteorite. The data show that this transition is unlikely driven by
     impurity such as chromite and seems to be rather an intrinsic property
     of troilite. In this study, we unambiguously exclude the relation of
     this transition to the structural rearrangement like the Morin
     transition in hematite. Similarly, in-field Mssbauer data do not support
     the change of the canting angle in the spin structure of FeS above and
     below the transition. Mssbauer, XRD, and magnetic data, newly measured
     also for troilite from the Bruderheim L6 chondrite, demonstrate that
     both studied troilite samples exhibit nearly the same magnetic and
     structural characteristics. Thus, the nature of the transition occurring
     at approximate to 70 K in both samples has identical characteristics and
     its detection can be used as a simple general marker for highly
     stoichiometric FeS systems.,
  DOI = 10.1029/2011JB008232,
  Article-Number = B11205,
  ISSN = 0148-0227,
  Unique-ID = ISI:000297257000001,
  

• R. Herchel, J. Tucek, Z. Travnicek, D. Petridis, and R. Zboril, “Crystal Water Molecules as Magnetic Tuners in Molecular Metamagnets
  Exhibiting Antiferro-Ferro-Paramagnetic Transitions,” INORGANIC CHEMISTRY, vol. 50, iss. 18, pp. 9153-9163, 2011.
  [Bibtex]

  @article ISI:000294699700054,
  Author = Herchel, Radovan and Tucek, Jiri and Travnicek, Zdenek and Petridis,
     Dimitris and Zboril, Radek,
  Title = Crystal Water Molecules as Magnetic Tuners in Molecular Metamagnets
     Exhibiting Antiferro-Ferro-Paramagnetic Transitions,
  Journal = INORGANIC CHEMISTRY,
  Year = 2011,
  Volume = 50,
  Number = 18,
  Pages = 9153-9163,
  Month = SEP 19,
  Abstract = We studied the effects of the number of crystal water molecules on the
     magnetic behavior of \[Ni(en)(2)](3)[Fe(CN)(6)](2)center dot
     xH(2)O\(n) (1-3) (where en = ethylenediamine and x = 3, 2, or 0)
     coordination polymers by (57)Fe Mossbauer spectroscopy, single-crystal
     X-ray diffraction, and magnetization measurements. Magnetic phase
     diagrams constructed for all three compounds indicate that they behave
     as metamagnets exhibiting very rare field-induced
     antiferro-ferro-paramagnetic transitions. The number of crystal water
     molecules has a major effect on the Neel temperature, critical field,
     and magnetic hardness of the compounds in the ferromagnetic state.
     Moreover, the systems behave as molecular magnetic sponges, changing
     their magnetic properties due to the controllable and reversible
     dehydration/hydration process.,
  DOI = 10.1021/ic201358c,
  ISSN = 0020-1669,
  Unique-ID = ISI:000294699700054,
  

• L. Machala, J. Tucek, and R. Zboril, “Polymorphous Transformations of Nanometric Iron(III) Oxide: A Review,” CHEMISTRY OF MATERIALS, vol. 23, iss. 14, pp. 3255-3272, 2011.
  [Bibtex]

  @article ISI:000292850700001,
  Author = Machala, Libor and Tucek, Jiri and Zboril, Radek,
  Title = Polymorphous Transformations of Nanometric Iron(III) Oxide: A Review,
  Journal = CHEMISTRY OF MATERIALS,
  Year = 2011,
  Volume = 23,
  Number = 14,
  Pages = 3255-3272,
  Month = JUL 26,
  Abstract = There is great interest in iron oxides, especially in nanosized form,
     for both fundamental and practical reasons. Because of its polymorphism,
     iron(III) oxide (ferric oxide, Fe(2)O(3)) is one of the most interesting
     and potentially useful phases of the iron oxides. Each of the four
     different known crystalline Fe(2)O(3) polymorphs (alpha-, beta-, gamma-,
     and epsilon-Fe(2)O(3)) has unique biochemical, magnetic, catalytic, and
     other properties that make it suitable for specific technical and
     biomedical applications. High temperature treatment is a key step in
     most syntheses of iron(III) oxides but often triggers polymorphous
     transformations that result in the formation of undesired mixtures of
     Fe(2)O(3) polymorphs. It is therefore important to control the
     parameters that induce polymorphous transformations when seeking to
     prepare a given Fe(2)O(3) polymorph as a single phase; identifying and
     understanding these parameters is a major challenge in the study of the
     polymorphism of solid compounds. This review discusses the dependence of
     the mechanism and kinetics of the polymorphous transformations of
     Fe(2)O(3) on the intrinsic properties of the material (polymorph
     structure, particle size, particle morphology, surface coating, particle
     aggregation, incorporation of particles within a matrix) and external
     parameters of synthetic and/or natural conditions such as temperature,
     atmosphere, and pressure. The high-temperature and high-pressure induced
     transformations of Fe(2)O(3) are reviewed in detail. In addition, the
     question of whether different Fe(2)O(3) polymorphs are formed
     sequentially or simultaneously during thermal processes is discussed
     extensively, with reference to the experimental results that have been
     invoked to support these two different mechanisms. The use of selected
     analytical tools in studying the polymorphous transformations of
     Fe(2)O(3) is also discussed, with particular emphasis on in situ
     approaches. Finally, key objectives for future research in this area are
     highlighted: (i) the development of more sophisticated kinetic control
     of the gamma-Fe(2)O(3) -> epsilon-Fe(2)O(3) phase transformation; (ii)
     investigation of particle morphology changes during the polymorphous
     transformations of Fe(2)O(3); and (iii) the study of high-pressure
     induced phase transformations of Fe(2)O(3) polymorphs other than
     alpha-Fe(2)O(3).,
  DOI = 10.1021/cm200397g,
  ISSN = 0897-4756,
  Unique-ID = ISI:000292850700001,
  

• R. Prucek, J. Tucek, M. Kilianova, A. Panacek, L. Kvitek, J. Filip, M. Kolar, K. Tomankova, and R. Zboril, “The targeted antibacterial and antifungal properties of magnetic
  nanocomposite of iron oxide and silver nanoparticles,” BIOMATERIALS, vol. 32, iss. 21, pp. 4704-4713, 2011.
  [Bibtex]

  @article ISI:000291571400003,
  Author = Prucek, Robert and Tucek, Jiri and Kilianova, Martina and Panacek, Ales
     and Kvitek, Libor and Filip, Jan and Kolar, Milan and Tomankova,
     Katerina and Zboril, Radek,
  Title = The targeted antibacterial and antifungal properties of magnetic
     nanocomposite of iron oxide and silver nanoparticles,
  Journal = BIOMATERIALS,
  Year = 2011,
  Volume = 32,
  Number = 21,
  Pages = 4704-4713,
  Month = JUL,
  Abstract = Two types of magnetic binary nanocomposites, Ag@Fe(3)O(4) and
     gamma-Fe(2)O(3)@Ag, were synthesized and characterized and their
     antibacterial activities were tested. As a magnetic component, Fe(3)O(4)
     (magnetite) nanoparticles with an average size of about 70 nm and
     monodisperse gamma-Fe(2)O(3) (maghemite) nanoparticles with an average
     size of 5 nm were used. Nanocomposites were prepared via in situ
     chemical reduction of silver ions by maltose in the presence of
     particular magnetic phase and molecules of polyacrylate serving as a
     spacer among iron oxide and silver nanoparticles. In the case of the
     Ag@Fe(3)O(4) nanocomposite, silver nanoparticles, caught at the surfaces
     of Fe(3)O(4) nanocrystals, were around 5 nm in a size. On the contrary,
     in the case of the gamma-Fe(2)O(3)@Ag nanocomposite, ultrafine
     gamma-Fe(2)O(3) nanoparticles surrounded silver nanoparticles ranging in
     a size between 20 and 40 nm. In addition, the molecules of polyacrylate
     in this nanocomposite type suppress considerably interparticle magnetic
     interactions as proved by magnetization measurements. Both synthesized
     nanocomposites exhibited very significant antibacterial and antifungal
     activities against ten tested bacterial strains (minimum inhibition
     concentrations (MIC) from 15.6 mg/L to 125 mg/L) and four candida
     species (MIC from 1.9 mg/L to 31.3 mg/L). Moreover, acute nanocomposite
     cytotoxicity against mice embryonal fibroblasts was observed at
     concentrations of higher than 430 mg/L (Ag@Fe(3)O(4)) and 292 mg/L
     (gamma-Fe(2)O(3)@Ag). With respect to the non-cytotoxic nature of the
     polyacrylate linker, both kinds of silver nanocomposites are well
     applicable for a targeted magnetic delivery of silver nanoparticles in
     medicinal and disinfection applications. (C) 2011 Elsevier Ltd. All
     rights reserved.,
  DOI = 10.1016/j.biomaterials.2011.03.039,
  ISSN = 0142-9612,
  Unique-ID = ISI:000291571400003,
  

• V. Prochazka, H. Stepankova, V. Chlan, J. Tucek, J. Cuda, K. Kouril, J. Filip, and R. Zboril, “Electric field gradient in FeTiO(3) by nuclear magnetic resonance and ab
  initio calculations,” JOURNAL OF PHYSICS-CONDENSED MATTER, vol. 23, iss. 20, 2011.
  [Bibtex]

  @article ISI:000290212300014,
  Author = Prochazka, V. and Stepankova, H. and Chlan, V. and Tucek, J. and Cuda,
     J. and Kouril, K. and Filip, J. and Zboril, R.,
  Title = Electric field gradient in FeTiO(3) by nuclear magnetic resonance and ab
     initio calculations,
  Journal = JOURNAL OF PHYSICS-CONDENSED MATTER,
  Year = 2011,
  Volume = 23,
  Number = 20,
  Month = MAY 25,
  Abstract = Temperature dependence of nuclear magnetic resonance (NMR) spectra of
     (47)Ti and (49)Ti in polycrystalline ilmenite FeTiO(3) was measured in
     the range from 5 to 300 K under an external magnetic field of 9.401 T.
     NMR spectra collected between 300 and 77 K exhibit a resolved quadrupole
     splitting. The electric field gradient (EFG) tensor was evaluated for Ti
     nuclei and the ratio of (47)Ti and (49)Ti nuclear quadrupole moments was
     refined during the fitting procedure. Below 77 K, the fine structure of
     quadrupole splitting disappears due to the enormous increase of
     anisotropy.
     As a counterpart, ab initio calculations were performed using full
     potential augmented plane waves + local orbitals. The calculated EFG
     tensors for Ti and Fe were compared to the experimental ones evaluated
     from NMR and the Mossbauer spectroscopy experiments.,
  DOI = 10.1088/0953-8984/23/20/205503,
  Article-Number = 205503,
  ISSN = 0953-8984,
  Unique-ID = ISI:000290212300014,
  

2010

• J. Tucek, R. Zboril, A. Namai, and S. Ohkoshi, “epsilon-Fe(2)O(3): An Advanced Nanomaterial Exhibiting Giant Coercive
  Field, Millimeter-Wave Ferromagnetic Resonance, and Magnetoelectric
  Coupling,” CHEMISTRY OF MATERIALS, vol. 22, iss. 24, pp. 6483-6505, 2010.
  [Bibtex]

  @article ISI:000285429000001,
  Author = Tucek, Jiri and Zboril, Radek and Namai, Asuka and Ohkoshi, Shin-ichi,
  Title = epsilon-Fe(2)O(3): An Advanced Nanomaterial Exhibiting Giant Coercive
     Field, Millimeter-Wave Ferromagnetic Resonance, and Magnetoelectric
     Coupling,
  Journal = CHEMISTRY OF MATERIALS,
  Year = 2010,
  Volume = 22,
  Number = 24,
  Pages = 6483-6505,
  Month = DEC 28,
  Abstract = Nanosized iron oxides still attract significant attention within the
     scientific community, because of their application-promising properties.
     Among them, epsilon-Fe(2)O(3) constitutes a remarkable phase, taking
     pride in a giant coercive field at room temperature, significant
     ferromagnetic resonance, and coupled magnetoelectric features that are
     not observed in any other simple metal oxide phase. In this work, we
     review basic structural and magnetic characteristics of this
     extraordinary nanomaterial with an emphasis on questionable and
     unresolved issues raised during its intense research in the past years.
     We show how a combination of various experimental techniques brings
     essential and valuable information, with regard to understanding the
     physicochemical properties of the E-polymorph of Fe(2)O(3), which
     remained unexplored for a long period of time. In addition, we
     recapitulate a series of synthetic routes that lead to the formation of
     epsilon-Fe(2)O(3), highlighting their advantages and drawbacks. We also
     demonstrate how magnetic properties of epsilon-Fe(2)O(3) can be tuned
     through the exploitation of various morphologies of epsilon-Fe(2)O(3)
     nanosystems, the alignment of epsilon-Fe(2)O(3) nanoobjects in a
     supporting matrix, and various degrees of cation substitution. Based on
     the current knowledge of the scientific community working in the field
     of epsilon-Fe(2)O(3), we finally arrive at two main future challenges:
     (i) the search for optimal synthetic conditions to prepare single-phase
     epsilon-Fe(2)O(3) with a high yield, desired size, morphology, and
     stability; and (ii) the search for a correct description of the magnetic
     behavior of epsilon-Fe(2)O(3) at temperatures below the characteristic
     magnetic ordering temperature.,
  DOI = 10.1021/cm101967h,
  ISSN = 0897-4756,
  Unique-ID = ISI:000285429000001,
  

• O. Schneeweiss, B. David, T. Zak, J. Filip, J. Tucek, R. Zboril, and M. Maslan, “Magnetic Interactions between Nanoparticles Formed during Calcination of
  Ferrihydrite,” ACTA PHYSICA POLONICA A, vol. 118, iss. 5, pp. 749-750, 2010.
  [Bibtex]

  @article ISI:000285797100015,
  Author = Schneeweiss, O. and David, B. and Zak, T. and Filip, J. and Tucek, J.
     and Zboril, R. and Maslan, M.,
  Title = Magnetic Interactions between Nanoparticles Formed during Calcination of
     Ferrihydrite,
  Journal = ACTA PHYSICA POLONICA A,
  Year = 2010,
  Volume = 118,
  Number = 5,
  Pages = 749-750,
  Month = NOV,
  Note = 14th Czech and Slovak Conference on Magnetism, Kosice, SLOVAKIA, JUN
     06-09, 2010,
  Organization = Safarik Univ, Fac Sci; Inst Phys, Slovak Acad Sci; Slovak Phys Soc,
  Abstract = Magnetic interactions between nanoparticles of magnetite Fe(3)O(4) and
     alpha-Fe Formed during calcination of ferrihydrite in H(2) at
     temperatures 533 - 713 K were studied The detailed phase analysis
     describes evolution of contents of magnetite and alpha-Fe Explanation of
     an anomalous course of magnetic moment characterized by a local maximum
     at an early stage of formation of nanoparticles is discussed,
  ISSN = 0587-4246,
  Unique-ID = ISI:000285797100015,
  

• J. Frydrych, L. Machala, M. Hermanek, I. Medrik, M. Mashlan, J. Tucek, J. Pechousek, and V. K. Sharma, “A nanocrystalline hematite film prepared from iron(III) chloride
  precursor,” THIN SOLID FILMS, vol. 518, iss. 21, pp. 5916-5919, 2010.
  [Bibtex]

  @article ISI:000280989100008,
  Author = Frydrych, Jiri and Machala, Libor and Hermanek, Martin and Medrik, Ivo
     and Mashlan, Miroslav and Tucek, Jiri and Pechousek, Jiri and Sharma,
     Virender K.,
  Title = A nanocrystalline hematite film prepared from iron(III) chloride
     precursor,
  Journal = THIN SOLID FILMS,
  Year = 2010,
  Volume = 518,
  Number = 21,
  Pages = 5916-5919,
  Month = AUG 31,
  Abstract = This paper deals with a simple and low-cost method developed to deposit
     hematite (alpha-Fe(2)O(3)) layers on a fluorine-doped tin oxide (FTO/F
     center dot SnO(2)) substrate by thermal decomposition of solid iron(III)
     chloride hexahydrate (FeCl(3) 6H(2)O) Deposition procedure takes place
     through chemical intermediate iron(III) oxide chloride (FeOCl) film. A
     crucial influence of atmosphere dynamics involved in the calcination
     process of FeOCl has been observed As-deposited films were characterized
     by means of Conversion Electron Mossbauer Spectroscopy (CEMS), Grazing
     Angle X-Ray Diffractometry (GAXRD), Atomic Force Microscopy (AFM),
     Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX)
     analysis Final nanocrystalline hematite film with a cactus-field-like
     design consists of 20 nm thick porous crystal plates. A process of
     hematite doping by tin atoms from substrate coating is also discussed
     (C) 2010 Elsevier B V. All rights reserved.,
  DOI = 10.1016/j.tsf.2010.05.081,
  ISSN = 0040-6090,
  Unique-ID = ISI:000280989100008,
  

• P. Dallas, J. Tucek, D. Jancik, M. Kolar, A. Panacek, and R. Zboril, “Magnetically Controllable Silver Nanocomposite with Multifunctional
  Phosphotriazine Matrix and High Antimicrobial Activity,” ADVANCED FUNCTIONAL MATERIALS, vol. 20, iss. 14, pp. 2347-2354, 2010.
  [Bibtex]

  @article ISI:000280427000019,
  Author = Dallas, Panagiotis and Tucek, Jiri and Jancik, Dalibor and Kolar, Milan
     and Panacek, Ales and Zboril, Radek,
  Title = Magnetically Controllable Silver Nanocomposite with Multifunctional
     Phosphotriazine Matrix and High Antimicrobial Activity,
  Journal = ADVANCED FUNCTIONAL MATERIALS,
  Year = 2010,
  Volume = 20,
  Number = 14,
  Pages = 2347-2354,
  Month = JUL 23,
  Abstract = A recently developed multi-functional phosphotriazine-based polymer is
     used as a matrix for embedding gamma-Fe(2)O(3) nanoparticles as well as
     a suitable chemical template for surface modification with silver
     nanoparticles. For the; primary magnetic modification, maghemite
     nanoparticles are surface modified with oleic acid in order to render
     them organophilic and to prevent the aggregation of the nanoparticles.
     This aggregation could occur as the polymer synthesis, based on reaction
     of phosphonitrilic chlorine and 1,4phenylenediamine, takes place in
     toluene. The surface active amine units of the polymer structure enable
     the reduction of silver cations to silver nanoparticles, which are well
     attached and finely dispersed on its surface. The developed
     nanocomposite represents one of the few magnetically controllable
     antibacterial agents based on silver nanoparticles. Magnetic
     measurements reveal the completely suppressed interactions among
     maghemite nanoparticles because of their perfect surface coating with an
     organic surfactant and fine dispersion inside the polymer matrix. This
     magnetic nanocomposite exhibits a high antibacterial and antifungal
     activity as proven by tests with nine bacterial strains and four candida
     (yeast genus) species. For the majority of the tested species, the
     minimum-inhibition concentrations are below 100 mg L(-1), which is
     comparable to their equivalent minimum-inhibition concentrations in
     colloidal silver systems.,
  DOI = 10.1002/adfm.200902370,
  ISSN = 1616-301X,
  Unique-ID = ISI:000280427000019,
  

• K. Sivula, R. Zboril, F. Le Formal, R. Robert, A. Weidenkaff, J. Tucek, J. Frydrych, and M. Graetzel, “Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared
  by a Solution-Based Colloidal Approach,” JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, vol. 132, iss. 21, pp. 7436-7444, 2010.
  [Bibtex]

  @article ISI:000278190600045,
  Author = Sivula, Kevin and Zboril, Radek and Le Formal, Florian and Robert, Rosa
     and Weidenkaff, Anke and Tucek, Jiri and Frydrych, Jiri and Graetzel,
     Michael,
  Title = Photoelectrochemical Water Splitting with Mesoporous Hematite Prepared
     by a Solution-Based Colloidal Approach,
  Journal = JOURNAL OF THE AMERICAN CHEMICAL SOCIETY,
  Year = 2010,
  Volume = 132,
  Number = 21,
  Pages = 7436-7444,
  Month = JUN 2,
  Abstract = Sustainable hydrogen production through photoelectrochemical water
     splitting using hematite (alpha-Fe(2)O(3)) is a promising approach for
     the chemical storage of solar energy, but is complicated by the
     material's nonoptimal optoelectronic properties. Nanostructuring
     approaches have been shown to increase the performance of hematite, but
     the ideal nanostructure giving high efficiencies for all absorbed light
     wavelengths remains elusive. Here, we report for the first time
     mesoporous hematite photoelectodes prepared by a solution-based
     colloidal method which yield water-splitting photocurrents of 0.56 mA
     cm(-2) under standard conditions (AM 1.5G 100 mW cm(-2), 1.23 V vs
     reversible hydrogen electrode, RHE) and over 1.0 mA cm(-2) before the
     dark current onset (1.55 V vs RHE). The sintering temperature is found
     to increase the average particle size, and have a drastic effect on the
     photoactivity. X-ray photoelectron spectroscopy and magnetic
     measurements using a SQUID magnetometer link this effect to the
     diffusion and incorporation of dopant atoms from the transparent
     conducting substrate. In addition, examining the optical properties of
     the films reveals a considerable change in the absorption coefficient
     and onset properties, critical aspects for hematite as a solar energy
     converter, as a function of the sintering temperature. A detailed
     investigation into hematite's crystal structure using powder X-ray
     diffraction with Rietveld refinement to account for these effects
     correlates an increase in a C(3v)-type crystal lattice distortion to the
     improved optical properties.,
  DOI = 10.1021/ja101564f,
  ISSN = 0002-7863,
  Unique-ID = ISI:000278190600045,
  

• R. Prochazka, P. Tucek, J. Tucek, J. Marek, M. Mashlan, and J. Pechousek, “Statistical analysis and digital processing of the Mossbauer spectra,” MEASUREMENT SCIENCE & TECHNOLOGY, vol. 21, iss. 2, 2010.
  [Bibtex]

  @article ISI:000273729300008,
  Author = Prochazka, Roman and Tucek, Pavel and Tucek, Jiri and Marek, Jaroslav
     and Mashlan, Miroslav and Pechousek, Jiri,
  Title = Statistical analysis and digital processing of the Mossbauer spectra,
  Journal = MEASUREMENT SCIENCE \& TECHNOLOGY,
  Year = 2010,
  Volume = 21,
  Number = 2,
  Month = FEB,
  Abstract = This work is focused on using the statistical methods and development of
     the filtration procedures for signal processing in Mossbauer
     spectroscopy. Statistical tools for noise filtering in the measured
     spectra are used in many scientific areas. The use of a pure statistical
     approach in accumulated Mossbauer spectra filtration is described. In
     Mossbauer spectroscopy, the noise can be considered as a Poisson
     statistical process with a Gaussian distribution for high numbers of
     observations. This noise is a superposition of the non-resonant photons
     counting with electronic noise ( from. gamma-ray detection and
     discrimination units), and the velocity system quality that can be
     characterized by the velocity nonlinearities. The possibility of a
     noise-reducing process using a new design of statistical filter
     procedure is described. This mathematical procedure improves the
     signal-to-noise ratio and thus makes it easier to determine the
     hyperfine parameters of the given Mossbauer spectra. The filter
     procedure is based on a periodogram method that makes it possible to
     assign the statistically important components in the spectral domain.
     The significance level for these components is then feedback-controlled
     using the correlation coefficient test results. The estimation of the
     theoretical correlation coefficient level which corresponds to the
     spectrum resolution is performed. Correlation coefficient test is based
     on comparison of the theoretical and the experimental correlation
     coefficients given by the Spearman method. The correctness of this
     solution was analyzed by a series of statistical tests and confirmed by
     many spectra measured with increasing statistical quality for a given
     sample ( absorber). The effect of this filter procedure depends on the
     signal-to-noise ratio and the applicability of this method has binding
     conditions.,
  DOI = 10.1088/0957-0233/21/2/025107,
  Article-Number = 025107,
  ISSN = 0957-0233,
  Unique-ID = ISI:000273729300008,
  

• V. Tzitzios, G. Basina, A. Bakandritsos, C. G. Hadjipanayis, H. Mao, D. Niarchos, G. C. Hadjipanayis, J. Tucek, and R. Zboril, “Immobilization of magnetic iron oxide nanoparticles on laponite discs -
  an easy way to biocompatible ferrofluids and ferrogels,” JOURNAL OF MATERIALS CHEMISTRY, vol. 20, iss. 26, pp. 5418-5428, 2010.
  [Bibtex]

  @article ISI:000279046200007,
  Author = Tzitzios, Vassilios and Basina, Georgia and Bakandritsos, Aristides and
     Hadjipanayis, Costas G. and Mao, Hui and Niarchos, Dimitrios and
     Hadjipanayis, George C. and Tucek, Jiri and Zboril, Radek,
  Title = Immobilization of magnetic iron oxide nanoparticles on laponite discs -
     an easy way to biocompatible ferrofluids and ferrogels,
  Journal = JOURNAL OF MATERIALS CHEMISTRY,
  Year = 2010,
  Volume = 20,
  Number = 26,
  Pages = 5418-5428,
  Abstract = Magnetic nanocomposites containing iron oxide (maghemite -
     gamma-Fe(2)O(3)) nanoparticles, embedded in a synthetic clay matrix
     (laponite) were prepared by a new one step chemical route and
     characterized by TEM, XRD, magnetization measurements, Mossbauer
     spectroscopy, DLS, and MRI measurements. The synthesis procedure leads
     to non-stoichiometric gamma-Fe(2)O(3) with a controllable content in the
     nanocomposite. Magnetic nanoparticles incorporated in the diamagnetic
     clay matrix exhibit a mean diameter of 13 nm and superparamagnetic
     behaviour with a high saturation magnetization achievable at low applied
     magnetic fields. The in-field Mossbauer spectra and ZFC/FC magnetization
     curves reveal a perfect ferrimagnetic ordering within nanoparticles with
     negligible spin frustration and interparticle interactions due to the
     incorporation of maghemite nanoparticles into the nanocrystalline
     laponite matrix, thus, significantly avoiding their clustering and
     agglomeration. Magnetic iron oxide nanoparticles embedded in the
     laponite matrix exhibit strong T(2)-weighted MRI contrast. The
     gamma-Fe(2)O(3)/laponite nanocomposite particles have a 200 nm
     hydrodynamic diameter and form very stable hydrosols and/or hydrogels
     depending on their concentration in water.,
  DOI = 10.1039/c0jm00061b,
  ISSN = 0959-9428,
  Unique-ID = ISI:000279046200007,
  

• A. Bakandritsos, G. Mattheolabakis, R. Zboril, N. Bouropoulos, J. Tucek, D. G. Fatouros, and K. Avgoustakis, “Preparation, stability and cytocompatibility of magnetic/PLA-PEG hybrids,” NANOSCALE, vol. 2, iss. 4, pp. 564-572, 2010.
  [Bibtex]

  @article ISI:000276469800015,
  Author = Bakandritsos, Aristides and Mattheolabakis, George and Zboril, Radek and
     Bouropoulos, Nikolaos and Tucek, Jiri and Fatouros, Dimitrios G. and
     Avgoustakis, Konstantinos,
  Title = Preparation, stability and cytocompatibility of magnetic/PLA-PEG hybrids,
  Journal = NANOSCALE,
  Year = 2010,
  Volume = 2,
  Number = 4,
  Pages = 564-572,
  Abstract = Hybrid nanocolloids based on biodegradable polymers of poly(lactide)
     (PLA) or poly(lactide)-block-poly(ethylene glycol) (PLA-PEG) and
     hydrophobic iron oxide magnetic nanoparticles (MNPs) of ca. 5 nm are
     prepared via a self-assembly route. The magnetic nanoparticles are
     organized in superclusters inside the hydrophobic core of PLA-PEG
     micelles or cholate-stabilized PLA nanospheres. The hydrodynamic
     diameter of MNPs-loaded PLA nanospheres is similar to 250 nm, whereas
     that of MNPs-loaded PLA-PEG micelles is much lower (similar to 100 nm)
     and thus compatible with applications where prolonged blood circulation
     is required. The PLA-PEG micelles exhibit high encapsulation efficiency
     for the MNPs, imparting a saturation magnetization value to the hybrid
     of 8.4 emu g(-1). Both hybrid colloids display magnetic properties of a
     non-interacting assembly of superparamagnetic particles and a low
     blocking temperature, both of which are key attributes for colloidally
     stable ferrofluids. Furthermore, the PLA-PEG magnetic hybrids display
     remarkable colloidal stability at high ionic strength, temperature and
     in human blood plasma, while the estimated critical micelle
     concentration of ca. 2 x 10(-5) mM (0.3 mg L(-1)) indicates the low
     probability of the colloids dissociation in the blood compartment. They
     were also found to be non-toxic to human cells in vitro. The results
     underline the potential of the magnetic/PLA-PEG hybrids and encourage
     further research for their in vivo biomedical applications.,
  DOI = 10.1039/b9nr00253g,
  ISSN = 2040-3364,
  Unique-ID = ISI:000276469800015,
  

• J. Cuda, R. Zboril, O. Schneeweiss, J. Tucek, V. Prochazka, M. Maslan, and P. Tucek, “Mossbauer Study and Macroscopic/Global Magnetic Behavior of Powdered
  Ilmenite (FeTiO(3)) Sample,” in MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE – 2010, 2010, pp. 55-67.
  [Bibtex]

  @inproceedings ISI:000281606200008,
  Author = Cuda, J. and Zboril, R. and Schneeweiss, O. and Tucek, J. and Prochazka,
     V. and Maslan, M. and Tucek, P.,
  Editor = Tucek, J and Miglierini, M,
  Title = Mossbauer Study and Macroscopic/Global Magnetic Behavior of Powdered
     Ilmenite (FeTiO(3)) Sample,
  Booktitle = MOSSBAUER SPECTROSCOPY IN MATERIALS SCIENCE - 2010,
  Series = AIP Conference Proceedings,
  Year = 2010,
  Volume = 1258,
  Pages = 55-67,
  Note = International Conference on Mossbauer Spectroscopy in Materials Science,
     Liptovsky Jan, SLOVAKIA, JAN 31-FEB 05, 2010,
  Abstract = In this article, the commercial synthetic powdered sample of ilmenite
     (FeTiO(3)) has been re-examined by Mossbauer spectroscopy in the
     paramagnetic regime from 77 K to 280 K and in a magnetically ordered
     state below 57 K. The effective vibrating mass and the Debye temperature
     was found to be (78 +/- 3) amu and (359 +/- 27) K, respectively. The two
     sextet components were used for correct fitting of the Mossbauer spectra
     recorded at 5 K and 45 K in an external magnetic field of 5 T. Moreover,
     the macroscopic magnetic measurements were carried out by an MPMS XL-7
     magnetometer to determine a temperature dependence of the molar
     susceptibility and hysteresis loops of this sample. The Mossbauer
     spectra and magnetization measurements confirm that below the ordering
     temperature of ilmenite, it behaves as a non-ideal antiferromagnetic
     material with a significant magnetic hardening at low temperatures. In
     addition, the magnetic molar susceptibility follows a Curie-Weiss law
     with C(m) = 5.8 x 10(-5) K m(3)/mol, and Weiss temperature theta(p) =
     30.6 K.,
  DOI = 10.1063/1.3473899,
  ISSN = 0094-243X,
  ISBN = 978-0-7354-0806-7,
  Unique-ID = ISI:000281606200008,
  

• M. Tuckova, P. Tucek, J. Tucek, and L. Kubacek, “SEARCH FOR OPTIMAL WAY TO PRECISELY EVALUATE MAGNETIC RESPONSE OF
  IRON-OXIDE BASED NANOMATERIALS – A NEW STATISTICALLY-BASED APPROACH,” in NANOCON 2010, 2ND INTERNATIONAL CONFERENCE, 2010, pp. 478-484.
  [Bibtex]

  @inproceedings ISI:000286656400085,
  Author = Tuckova, Michaela and Tucek, Pavel and Tucek, Jiri and Kubacek, Lubomir,
  Book-Group-Author = TANGER Ltd,
  Title = SEARCH FOR OPTIMAL WAY TO PRECISELY EVALUATE MAGNETIC RESPONSE OF
     IRON-OXIDE BASED NANOMATERIALS - A NEW STATISTICALLY-BASED APPROACH,
  Booktitle = NANOCON 2010, 2ND INTERNATIONAL CONFERENCE,
  Year = 2010,
  Pages = 478-484,
  Note = 2nd NANOCON International Conference, Olomouc, CZECH REPUBLIC, OCT
     12-14, 2010,
  Abstract = The theory of nonlinear regression models along with the statistical
     theory of design of experiment have been employed to investigate the
     dependence of magnetization of gamma-Fe(2)O(3) nanosystem on an external
     magnetic field. Two analytical functions, each having different physical
     background, have been chosen to fit the experimental data and a degree
     of suitability of a particular function for a correct description of the
     magnetic response of the studied gamma-Fe(2)O(3) nanosystem has been
     then evaluated. Utilizing the approach of experiment design, an
     optimized measuring procedure of the hysteresis loop of the investigated
     gamma-Fe(2)O(3) nanosystem has been further proposed in order to improve
     the accuracy of estimations of nanosystem hysteresis-loop parameters and
     to reduce the financial costs and time consumption of the experiment.,
  ISBN = 978-80-87294-19-2,
  Unique-ID = ISI:000286656400085,
  

2009

• K. Kluchova, R. Zboril, J. Tucek, M. Pecova, L. Zajoncova, I. Safarik, M. Mashlan, I. Markova, D. Jancik, M. Sebela, H. Bartonkova, V. Bellesi, P. Novak, and D. Petridis, “Superparamagnetic maghemite nanoparticles from solid-state synthesis -
  Their functionalization towards peroral MRI contrast agent and magnetic
  carrier for trypsin immobilization,” BIOMATERIALS, vol. 30, iss. 15, pp. 2855-2863, 2009.
  [Bibtex]

  @article ISI:000265328100001,
  Author = Kluchova, Katerina and Zboril, Radek and Tucek, Jiri and Pecova,
     Michaela and Zajoncova, Ludmila and Safarik, Ivo and Mashlan, Miroslav
     and Markova, Ingrid and Jancik, Dalibor and Sebela, Marek and
     Bartonkova, Helena and Bellesi, Vassiliki and Novak, Pavel and Petridis,
     Dimitris,
  Title = Superparamagnetic maghemite nanoparticles from solid-state synthesis -
     Their functionalization towards peroral MRI contrast agent and magnetic
     carrier for trypsin immobilization,
  Journal = BIOMATERIALS,
  Year = 2009,
  Volume = 30,
  Number = 15,
  Pages = 2855-2863,
  Month = MAY,
  Abstract = Nearly monodispersed superparamagnetic maghemite nanoparticles (15-20
     nm) were prepared by a one-step thermal decomposition of iron(II)
     acetate in air at 400 degrees C. The presented synthetic route is
     simple, cost effective and allows to prepare the high-quality
     superparamagnetic particles in a large scale. The as-prepared particles
     were exploited for the development of magnetic nanocomposites with the
     possible applicability in medicine and biochemistry. For the purposes of
     the MRI diagnostics, the maghemite particles were simply dispersed in
     the bentonite matrix. The resulting nanocomposite represents very
     effective and cheap oral negative contrast agent for MRI of the
     gastrointestinal tract and reveals excellent contrast properties, fully
     comparable with those obtained for commercial contrast material. The
     results of the clinical research of this maghemite-bentonite contrast
     agent for imaging of the small bowel are discussed. For biochemical
     applications, the primary functionalization of the prepared maghemite
     nanoparticles with chitosan was performed. In this way, a highly
     efficient magnetic carrier for protein immobilization was obtained as
     demonstrated by conjugating thermostable raffinose-modified trypsin
     (RMT) using glutaraldehyde. The covalent conjugation resulted in a
     further increase in trypsin thermostability (T(50) = 61 degrees C) and
     elimination of its autolysis. Consequently, the immobilization of RMT
     allowed fast in-solution digestion of proteins and their identification
     by MALDI-TOF mass spectrometry. (C) 2009 Elsevier Ltd. All rights
     reserved.,
  DOI = 10.1016/j.biomaterials.2009.02.023,
  ISSN = 0142-9612,
  Unique-ID = ISI:000265328100001,
  

• V. Belessi, D. Lambropoulou, I. Konstantinou, R. Zboril, J. Tucek, D. Jancik, T. Albanis, and D. Petridis, “Structure and photocatalytic performance of magnetically separable
  titania photocatalysts for the degradation of propachlor,” APPLIED CATALYSIS B-ENVIRONMENTAL, vol. 87, iss. 3-4, pp. 181-189, 2009.
  [Bibtex]

  @article ISI:000264948000006,
  Author = Belessi, V. and Lambropoulou, D. and Konstantinou, I. and Zboril, R. and
     Tucek, J. and Jancik, D. and Albanis, T. and Petridis, D.,
  Title = Structure and photocatalytic performance of magnetically separable
     titania photocatalysts for the degradation of propachlor,
  Journal = APPLIED CATALYSIS B-ENVIRONMENTAL,
  Year = 2009,
  Volume = 87,
  Number = 3-4,
  Pages = 181-189,
  Month = APR 7,
  Abstract = A magnetic photocatalyst was prepared by modification of TiO(2)
     nanoparticles (Degussa P25) with nanocrystalline gamma-Fe(2)O(3)
     nanoparticles through a protective lining made up of two oppositely
     charged polyelectrolytes. As-prepared magnetically separable
     photocatalysts differing in gamma-Fe(2)O(3) loading (3, 8, 13, 20 and 30
     wt.\%) were characterized by XRD, TEM, thermal analysis, Mossbauer and
     magnetic measurements. The photocatalytic efficiency of the
     nanocomposite catalysts was evaluated using a chloroacetanilide
     herbicide (propachlor) in water as model compound. The primary
     degradation of propachlor followed pseudo-first-order kinetics according
     to the Langmuir-Hinshelwood model. Generally, all magnetic
     photocatalysts exhibit good catalytic activity towards organic
     pollutants, do not suffer from photodissolution and can be reused
     several times without any decrease in their photocatalytic activity. (C)
     2008 Published by Elsevier B.V.,
  DOI = 10.1016/j.apcatb.2008.09.012,
  ISSN = 0926-3373,
  Unique-ID = ISI:000264948000006,
  

• M. Mashlan, H. Bartonkova, D. Jancik, J. Tucek, and P. Martinec, “Iron oxide modified minerals,” in ISIAME 2008, 2009, pp. 481-487.
  [Bibtex]

  @inproceedings ISI:000273775100063,
  Author = Mashlan, M. and Bartonkova, H. and Jancik, D. and Tucek, J. and
     Martinec, P.,
  Editor = Kuzmann, E and Lazar, K,
  Title = Iron oxide modified minerals,
  Booktitle = ISIAME 2008,
  Year = 2009,
  Pages = 481-487,
  Note = 7th International Symposium on the Industrial Applications of the
     Mossbauer Effect (ISIAME 2008), Eotvos Lorand Univ, Budapest, HUNGARY,
     AUG 17-22, 2008,
  Organization = Inst Isotopes; Hungarian Chem Soc,
  Abstract = Composites of iron oxide nanoparticles immobilized on the surface of
     various clay mineral matrices (muscovite, montmorillonite and
     vermiculite) have been prepared by the alkaline oxidative hydrolysis of
     iron sulphate in the presence of mineral matrices. The composites have
     been studied by Mossbauer spectroscopy, XRD, TEM and SQUID.
     Correspondence between the hyperfine parameters and the iron oxide
     particle size and magnetic behaviour has been proved. The prepared
     composites differ in magnetic properties., size and morphology of the
     iron oxide particles.,
  DOI = 10.1007/978-3-642-01369-0\_64,
  ISBN = 978-3-642-01369-0,
  Unique-ID = ISI:000273775100063,
  

2008

• V. Belessi, R. Zboril, J. Tucek, M. Mashlan, V. Tzitzios, and D. Petridis, “Ferrofluids from magnetic-chitosan hybrids,” CHEMISTRY OF MATERIALS, vol. 20, iss. 10, pp. 3298-3305, 2008.
  [Bibtex]

  @article ISI:000256056600011,
  Author = Belessi, V. and Zboril, R. and Tucek, J. and Mashlan, M. and Tzitzios,
     V. and Petridis, D.,
  Title = Ferrofluids from magnetic-chitosan hybrids,
  Journal = CHEMISTRY OF MATERIALS,
  Year = 2008,
  Volume = 20,
  Number = 10,
  Pages = 3298-3305,
  Month = MAY 27,
  Abstract = Magnetic nanoparticles coated with chitosan or quaternized chitosan were
     synthesized by a new route and characterized by X-ray diffraction (XRD),
     transmission electron microscopy (TEM), temperature dependent and
     in-field Mossbauer spectroscopy, FTIR, thermal analysis (TG/DTA), zeta
     potential, and magnetic measurements. The prepared ferrofluids were
     stable for a relatively long time. Mossbauer spectra recorded in an
     external magnetic field of 5 T establish the formation of
     ``nonstoichiometric magnetite'' exhibiting the perfect ferrimagnetic
     ordering with a low degree of spin canting and frustration. Magnetic
     measurements confirm the desired properties of the magnetic chitosan for
     biomedical applications including the superparamagnetic character at
     room temperature and a high saturation magnetization achievable at low
     applied fields. The successful and full capping of particles is
     indicated mainly from magnetic and DTA data through the suppressed
     interparticle interactions and a significant shift in the transformation
     temperature of the magnetic cores to hematite. The core-shell structure
     is definitely proved by TEM observations showing the well crystalline
     cubic particles with the log-normal size distribution between 10 and 40
     nm, which are fully coated with narrow shell of the chitosan matrix.,
  DOI = 10.1021/cm702990t,
  ISSN = 0897-4756,
  Unique-ID = ISI:000256056600011,
  

• J. Filip, E. Dachs, J. Tucek, M. Novak, and P. Bezdicka, “Low-temperature calorimetric and magnetic data for natural end-members
  of the axinite group,” AMERICAN MINERALOGIST, vol. 93, iss. 4, pp. 548-557, 2008.
  [Bibtex]

  @article ISI:000254657600007,
  Author = Filip, Jan and Dachs, Edgar and Tucek, Jiri and Novak, Milan and
     Bezdicka, Petr,
  Title = Low-temperature calorimetric and magnetic data for natural end-members
     of the axinite group,
  Journal = AMERICAN MINERALOGIST,
  Year = 2008,
  Volume = 93,
  Number = 4,
  Pages = 548-557,
  Month = APR,
  Abstract = The low-temperature heat capacities of natural near end-member minerals
     (about 95 mol\%, except tinzenite of about 34 mol\% on average) of the
     axinite group, previously characterized in detail by means of powder and
     single-crystal X-ray diffraction, electron microprobe, and Mossbauer
     spectroscopy, were measured by heat-pulse calorimetry using the Physical
     Properties Measurement System (Quantum Design) at temperatures between
     5(2) and 300 K. From these data, the following entropy values [in
     J/(mol center dot K)] of the natural samples at 298.15 K were derived:
     S-298,S-magnesioaxinite = 696.3 +/- 1.1, S-298,S-ferroaxinite = 743.5
     +/- 3.5, S-298,S-manganaxinite = 737.5 +/- 2.6, and S-298,S-tinzenite =
     758.1 +/- 2.8. For the end-memeber compositions, the corrected heat
     capacities at 298.15 K and standard third-law entropies of the axinites
     are [all in J/(mol center dot K)]:
     C-Pmagnesioaxinite degrees = 827.5 +/- 1.5 and S-magnesioaxinite degrees
     = 693.7 +/- 1.1, C-Pferroaxinite degrees = 841.8 +/- 3.3 and
     S-ferroaxinite degrees = 749.6 +/- 3.5, C-Pmanganaxinite degrees (=)
     849.1 +/- 2.5 and S-manganaxinite degrees = 737.8 +/- 2.6, and
     C-Ptinzenite degrees = 841.6 +/- 2.6, S-tinzenite degrees = 754.0 +/-
     2.8.
     The standard entropies of manganaxinite and tinzenite include
     contributions of 1.9 and 4.3 J/(mol center dot K) for the range 0-5 K
     evaluated based on a Schottky anomaly fitted to the low-T C-P values of
     these axinites. The lowest measured heat capacities of ferroaxinite
     indicate that a lambda-type C-P anomaly should exist between 0 and 2 K.
     Its likely contribution to the standard entropy was estimated as similar
     to 5.2 J/(mol center dot K). A low-temperature C-P anomaly below 15 K
     for ferroaxinite is well-explained by ferromagnetic ordering, whereas
     for manganaxinite by uncompensated antiferromagnetic ordering, and
     ferromagnetic by pure antiferromagnetic ordering.,
  DOI = 10.2138/am.2008.2680,
  ISSN = 0003-004X,
  Unique-ID = ISI:000254657600007,
  

2007

• K. Nomura, R. Zboril, J. Tucek, W. Kosaka, S. Ohkoshi, and I. Felner, “Substitution effects of barium and calcium on magnetic properties of
  A(x)Sr(1-x)(Fe(0.5)Ru(0.5))O(3) double perovskites (x=0.05, A=Ba,Ca),” JOURNAL OF APPLIED PHYSICS, vol. 102, iss. 1, 2007.
  [Bibtex]

  @article ISI:000248018300065,
  Author = Nomura, K. and Zboril, R. and Tucek, J. and Kosaka, W. and Ohkoshi, S.
     and Felner, I.,
  Title = Substitution effects of barium and calcium on magnetic properties of
     A(x)Sr(1-x)(Fe(0.5)Ru(0.5))O(3) double perovskites (x=0.05, A=Ba,Ca),
  Journal = JOURNAL OF APPLIED PHYSICS,
  Year = 2007,
  Volume = 102,
  Number = 1,
  Month = JUL 1,
  Abstract = A(x)Sr(1-x)(Fe(0.5)Ru(0.5))O(3) double perovskites (x=0.05 and A=Ba,Ca)
     were prepared by a sol-gel method and an effect of the cation
     substitution at the A site of the crystal structure of
     SrFe(0.5)Ru(0.5)O(3) on their magnetic properties was monitored by x-ray
     diffraction (XRD), magnetic measurements, transmission electron
     microscopy (TEM), scanning electron microscopy (SEM), and
     temperature-dependent and in-field (57)Fe Mossbauer spectroscopy. Both
     Ca- and Ba-substituted samples reveal the orthorhombic structure similar
     to the undoped perovskite; however, the cell volume changes with the
     substituting ion radius. TEM and SEM micrographs manifest agglomerated
     nanocrystalline samples with particle sizes of about 20-60, 15-50, and
     40-70 nm for the undoped, Ba-doped, and Ca-doped perovskites,
     respectively. Generally, the magnetic regime of both substituted and
     undoped perovskites can be described by a spin-glass behavior caused by
     a spin frustration. Among other factors, this is manifested by a
     nonsaturation of the hysteresis loops even at a high field of 50 kOe, by
     a low-temperature divergence of the zero-field-cooled and field-cooled
     magnetization curves, and by a cusp in the zero-field-cooled
     magnetization curve. The low-temperature spin-glass state is also
     supported by the in-field Mossbauer spectra, recorded on these systems.
     The isomer shift parameters, extracted from the Mossbauer spectra,
     confirm a high-spin iron(III) state with S=5/2. In contrast to the
     undoped and Ba-doped samples, the narrower distribution of the hyperfine
     magnetic fields, observed in the Ca-doped perovskite can be ascribed to
     the larger particles. Compared to the undoped sample, the field of
     maximum probability is higher in the Ca-substituted perovskite while it
     is reduced in the Ba-doped sample because of the effects of the chemical
     compression and expansion, respectively. In addition, the Ca-doped
     sample exhibits more negative Weiss temperature (Theta=-105 K) than that
     found for the Ba-substituted perovskite (Theta=-49 K), implying that
     doping with Ca at Sr sites of SrFe(0.5)Ru(0.5)O(3) perovskite structure
     provokes strengthening of antiferromagnetic interactions at the expense
     of the other ones. Furthermore, both substituted samples reveal
     significantly reduced coercive fields in the hysteresis loops recorded
     at 5 K, probably as a result of decreasing magnetocrystalline
     anisotropy. This is an indirect evidence of the essential influence of
     the substitution on the crystal growth of the synthesized particles. The
     role of SrRuO(3) and SrFeO(3) compounds, which have been detected in
     magnetic and Mossbauer measurements as admixtures, is discussed. (c)
     2007 American Institute of Physics.,
  DOI = 10.1063/1.2751101,
  Article-Number = 013907,
  ISSN = 0021-8979,
  Unique-ID = ISI:000248018300065,
  

2006

• J. Tucek, R. Zboril, and D. Petridis, “Maghemite nanoparticles by view of Mossbauer spectroscopy,” JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY, vol. 6, iss. 4, pp. 926-947, 2006.
  [Bibtex]

  @article ISI:000237069200004,
  Author = Tucek, J and Zboril, R and Petridis, D,
  Title = Maghemite nanoparticles by view of Mossbauer spectroscopy,
  Journal = JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY,
  Year = 2006,
  Volume = 6,
  Number = 4,
  Pages = 926-947,
  Month = APR,
  Abstract = A (57)Fe Mossbauer spectrometry applied in a broad range of temperatures
     and external magnetic fields is presented as a powerful investigating
     tool for the structural and magnetic characterization of maghemite
     (gamma-Fe(2)O(3)) nanoparticles, which presently constitute a modern
     advanced material used in various fields of scientific, technological,
     and biomedical interest. Reflections of structural and magnetic
     properties in the hyperfine parameters of Mossbauer spectra of
     nanomaghemite samples prepared by different routes with varying particle
     size distribution, particle morphology, and degree of interparticle
     interactions (isolated nanoparticles, powders, nanocomposites, films)
     are reviewed. Some crucial points concerning the description of the
     magnetic regime of strongly interacting maghemite nanoparticles are also
     briefly discussed with respect to their Mossbauer spectra.,
  DOI = 10.1166/jnn.2006.183,
  ISSN = 1533-4880,
  Unique-ID = ISI:000237069200004,
  

• O. Schneeweiss, R. Zboril, N. Pizurova, M. Mashlan, E. Petrovsky, and J. Tucek, “Novel solid-state synthesis of alpha-Fe and Fe(3)O(4) nanoparticles
  embedded in a MgO matrix,” NANOTECHNOLOGY, vol. 17, iss. 2, pp. 607-616, 2006.
  [Bibtex]

  @article ISI:000235221800045,
  Author = Schneeweiss, O and Zboril, R and Pizurova, N and Mashlan, M and
     Petrovsky, E and Tucek, J,
  Title = Novel solid-state synthesis of alpha-Fe and Fe(3)O(4) nanoparticles
     embedded in a MgO matrix,
  Journal = NANOTECHNOLOGY,
  Year = 2006,
  Volume = 17,
  Number = 2,
  Pages = 607-616,
  Month = JAN 28,
  Abstract = Thermally induced reduction of amorphous Fe(2)O(3) nanopowder (2-3 nm)
     with nanocrystalline Mg (similar to 20 nm) under a hydrogen atmosphere
     is presented as a novel route to obtain alpha-Fe and Fe(3)O(4) magnetic
     nanoparticles dispersed in a MgO matrix. The phase composition,
     structural and magnetic properties, size and morphology of the
     nanoparticles were monitored by x-ray diffraction, (57)Fe Mossbauer
     spectroscopy at temperatures of 24-300 K, transmission electron
     microscopy and magnetic measurements. Spherical magnetite nanoparticles
     prepared at a reaction temperature of 300 degrees C revealed a
     well-defined structure, with a ratio of tetrahedral to octahedral Fe
     sites of 1/2 being common for the bulk material. A narrow particle size
     distribution (20-30 nm) and high saturation magnetization (95 +/- 5 A
     m(2) kg(-1)) predispose the magnetite nanoparticles to various
     applications, including magnetic separation processes. The Verwey
     transition of Fe(3)O(4) nanocrystals was found to be decreased to about
     80 K. The deeper reduction of amorphous ferric oxide at 600 degrees C
     allows alpha-Fe (40-50 nm) nanoparticles to be synthesized with a
     coercive force of about 30 mT. They have a saturation magnetization 2.2
     times higher than that of synthesized magnetite nanoparticles, which
     corresponds well with the ratio usually found for the pure bulk phases.
     The magnetic properties of alpha-Fe nanocrystals combined with the high
     chemical and thermal stability of the MgO matrix makes the prepared
     nanocomposite useful for various magnetic applications.,
  DOI = 10.1088/0957-4484/17/2/044,
  ISSN = 0957-4484,
  Unique-ID = ISI:000235221800045,
  

2005

• J. Tucek and R. Zboril, “Zero-field and in-field Mossbauer spectroscopy as a tool for structural
  and magnetic characterization of maghemite (gamma-Fe(2)O(3))
  nanoparticles,” CZECHOSLOVAK JOURNAL OF PHYSICS, vol. 55, iss. 7, pp. 893-911, 2005.
  [Bibtex]

  @article ISI:000231635800014,
  Author = Tucek, J and Zboril, R,
  Title = Zero-field and in-field Mossbauer spectroscopy as a tool for structural
     and magnetic characterization of maghemite (gamma-Fe(2)O(3))
     nanoparticles,
  Journal = CZECHOSLOVAK JOURNAL OF PHYSICS,
  Year = 2005,
  Volume = 55,
  Number = 7,
  Pages = 893-911,
  Month = JUL,
  Note = International Colloquium on Mossbauer Spectroscopy in Materials Science,
     Vsemina, CZECH REPUBLIC, JUN 01-04, 2004,
  Abstract = Nowadays, nanoparticles of maghemite (gamma-Fe(2)O(3)) represent one of
     the most useful materials in modern advanced nanotechnological
     applications due to their superior magnetic properties. For their
     characterization, (57)Fe zero-field and in-field Mossbauer spectroscopy
     have proved themselves to be very powerful and effective tools which are
     crucial for an investigation of the local surrounding of iron atoms and
     observation of dynamic effects. The structural and magnetic
     characteristics of maghemite and its nanoparticles are thus discussed
     with regard to their zero-field and in-field Mossbauer spectra recorded
     at various temperatures and applied external magnetic fields. In
     addition, a special attention is also devoted to remarkable physical
     phenomena (superparamagnetism, spin canting) occurring largely in
     maghemite nanosized particles.,
  DOI = 10.1007/s10582-005-0091-1,
  ISSN = 0011-4626,
  Unique-ID = ISI:000231635800014,
  

2004

• R. Zboril, L. Machalal, M. Mashlan, J. Tucek, R. Muller, and O. Schneeweiss, “Magnetism of amorphous Fe2O3 nanopowders synthesized by solid-state
  reactions,” in SECOND SEEHEIM CONFERENCE ON MAGNETISM, PROCEEDINGS, 2004, pp. 3710-3716.
  [Bibtex]

  @inproceedings ISI:000227060600107,
  Author = Zboril, R and Machalal, L and Mashlan, M and Tucek, J and Muller, R and
     Schneeweiss, O,
  Editor = Ghafari, M and Enz, T and Hahn, H,
  Title = Magnetism of amorphous Fe2O3 nanopowders synthesized by solid-state
     reactions,
  Booktitle = SECOND SEEHEIM CONFERENCE ON MAGNETISM, PROCEEDINGS,
  Year = 2004,
  Pages = 3710-3716,
  Note = 2nd Seeheim Conference on Magnetism (SCM2004), Seeheim, GERMANY, JUN
     27-JUL 01, 2004,
  Organization = Deutsch Forsch Gemeinsch; Forsch Zentrum Karlsruhe; Darmstadt Univ
     Technol,
  Abstract = Monodispersed amorphous Fe2O3 nanoparticles with the size ranging from 1
     to 4 nm have been prepared by thermally induced oxidative decomposition
     of Prussian Blue, Fe-4[Fe(CN)(6)](3) in air. Amorphous nanopowders
     exhibit specific magnetic behaviour strongly affected by interparticle
     interactions and extremely low particle size with a high contribution of
     the surface anisotropy as illustrated by temperature dependent and
     external field Mossbauer spectroscopy and magnetization measurements
     (4-300 K). Some of the properties are in close similarity to those of
     spin glasses including the fast thermal variation of superparamagnetic
     fraction in the Mossbauer spectra, or the particle size independence of
     the blocking temperature, and non-saturation of magnetization even at 5
     K and magnetic field of 10 T. The reduced value of internal magnetic
     hyperfine field (similar to49 T at 5 K) and no indications of the
     tetrahedral Fe3+ sites in the 5T/5K external field Mossbauer spectra are
     the principal found differences in comparison with the magnetic
     behaviour of nanocrystalline gamma-Fe2O3. (C) 2004 WILEY-VCH Verlag GmbH
     \& Co. KGaA, Weinheim,
  ISBN = 3-527-40577-1,
  Unique-ID = ISI:000227060600107,