Abstract: A synthetic procedure based on thermal hydrolysis of iron(III) chloride solutions for the
preparation of hematite (α-Fe2O3) and ferricoxychloride (FeOCl) colloids consisting of
nanoparticles (NPs) is described. Transmission electron microscopy indicated that both colloids
consisted of particles smaller than 10 nm. X-ray diffraction measurements revealed transformation
of FeOCl NPs into α-Fe2O3 NPs after a few months. The phase transformation was explained in
terms of redissolution – recrystallization process. UV-vis spectroscopy was used for precise
determination of the band gap of α-Fe2O3.
Abstract: The sorption of ferric and ferrous ions from aqueous solutions on the silica powder,
obtained from colloidal dispersion of silica (silica sol), was studied as a function of their
concentrations and solution pH. The amount of sorbed ferric and ferrous ions increases with
increasing final pH of the solution. The sorption isotherms are of high-affinity type. A sorption
mechanism of ferric and ferrous ions from aqueous solutions on silica is proposed.
Abstract: Sonochemically assisted co-precipitation has been used to prepare nanosized manganesezinc-
ferrite powder. A suspension of constituent hydroxides was ultrasonically irradiated for various
times with high-intensity ultrasound radiation (20 kHz, 750 W) using a direct-immersion titanium
horn. The average grain size and magnetization of the synthesized MnZn-ferrite nanoparticles
gradually increases with the time of ultrasonic irradiation.
Abstract: The influence of the Co addition and synthesis route on desorption properties of MgH2
were investigated. Ball milling of MgH2-Co blends was performed under Ar using different
milling intensities and different weight ratios. Microstructural and morphological
characterization, performed by XRD and SEM, show a huge correlation with thermal stability
and hydrogen desorption properties investigated by DSC. A complex desorption behaviour is
correlated with the dispersion of the catalytic particles that appears to play a main role in
desorption performances. The optimum catalyst concentration was found to be around 10 wt.%,
while the optimum value of the ball to powder ratio was 10:1.
Abstract: In this paper the adsorption and oxidation of CO on nanocrystalline Au/γ-Fe2O3, Au/α-
Fe2O3, γ-Fe2O3 and a series of mixed ferrite with MnxZn1-xFe2O4 composition are investigated. The
catalysts were prepared by co-precipitation method and characterized using X-ray diffraction
(XRPD), specific surface (BET), transition electron spectroscopy (TEM) and magnetization
measurements. A temperature programmed desorption (TPD) study of the water and CO interaction
with nanocrystalline adsorbents is presented. The catalytic activities towards CO oxidation
increased in the following order: γ-Fe2O3 < MnxZn1-xFe2O4 < Au/γ-Fe2O3 .
Abstract: Advances in nanoscale electronics require superior ceramic powders, preferable prepared
with techniques for the direct synthesis of crystalline nanoparticles. Zinc ferrite (ZnFe2O4)
nanopowders were prepared by co-precipitation method, from nitrate precursors. Crystalline
powders having the single-phase cubic spinel structure were directly synthesized at temperature
≥80°C in the presence of NaOH. The obtained powders are agglomerated with ultra-fine crystallites
having the average crystallite size about 3-4 nm.
Abstract: One of the methods for powder synthesis that is both cost and time effective is the selfpropagating
room temperature synthesis. We applied this method to synthesize rare earth doped
ceria nanopowders. Since they exhibit very high ionic conductivity at intermediate temperatures
these compositions are attractive for a new generation of nanostructured ceramics applicable in
solid oxide fuel cells as electrolytes. In this paper we paid our attention to the reaction based on
methathetical pathway, whereby solid solution nanopowders of rare earth elements with ceria were
obtained at room temperature. Compositions of Ce1-xRexO2-δ (Re = Y , Nd) were synthesized with x
ranging from 0 to 0.20. The reaction course is discussed and the properties of the obtained powders
Abstract: Nanosized titanium dioxide (TiO2) powders in anatase phase were prepared by laserinduced
pyrolysis. Specific surface area of as-grown powders measured by BET method was
between 77 and 110 m2/g. The particle sizes (14.4-20.6 nm) estimated from these data coincide well
with the crystallite sizes (12.3-17.4 nm) determined by XRD measurements. The mean particle sizes
(35-41 nm) obtained from the subsequent SEM measurements refer to considerable agglomeration
of nanoparticles. Raman spectroscopy has been used to investigate the structural properties as well
as the changes under laser irradiation of TiO2 nanopowders. The blueshift and broadening of the
lowest frequency Eg Raman mode were analyzed using a phonon-confinement model which
includes strain effect and broadening associated with the size distribution. Influence of the
nonstoichiometry and anharmonic effects on this mode have been also investigated. Besides,
different changes in Raman spectra after the laser irradiation in vacuum were observed for the
nanopowders with different strain values.
Abstract: The yttrium-aluminium garnet phase (YAG) represents a suitable host material for solidstate
lasers and is widely used for various display applications being doped with rare-earth ions.
Introduction of Ce3+ ion as a luminescence centre transforms it from insulating to effective
phosphor material capable of emitting radiation in the visible spectrum. In this work Ce3+ doped
YAG powder was obtained via aerosol route using nitrate precursor solution. Well-crystallized
targeted phase was obtained after additional thermal treatment. A combination of different analysis
techniques (differential scanning calorimetry, X-ray powder diffraction, scanning electron
microscopy with determination of image metrology, energy dispersive spectroscopy, transmission
electron microscopy) is used to obtain detailed information about the structural and morphological
powder properties. The effects of both processing parameters and post annealing treatment
conditions are discussed from the viewpoint of establishing the best relationship between them and
produced YAG:Ce3+ crystal structure.
Abstract: Structural, magnetic and electrical properties of iron oxide nano-sized powders
synthesised electrochemically under various conditions are presented. The influence of the
temperature and current density of synthesis on particular powder characteristics is established.
Possibilities for co-existence of various phases and their impact on powder properties, as well as
feasible paths of phase relaxation and transition during non-isothermal heating are investigated, too.
In this way, optimal procedures for the preparation and stabilisation of iron oxides nano-sized
powders of different characteristics are evaluated.