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1.
Petra Šulcová Jan Večeřa Lucie Strnadlová 《Journal of Thermal Analysis and Calorimetry》2012,108(2):519-523
The compounds based on CeO2 belong to the group of high-temperature pigments. The principal of these pigments makes the host lattice of the CeO2, which is doped by terbium and zirconium ions, that lead to obtaining of the interesting dark orange colour. The research
is focused on three different methods of synthesis. The pigments have been prepared by the classical dry proces (i.e. solid-state
reaction) in the temperature range from 1,200 to 1,600 °C, by the precipitation and as the last method a simulation of ‘Mixer
Dryer Reactor’(MDR) under laboratory conditions (two-step process) was used. The aim was to improve and optimize the synthesis
conditions of studied pigments. The compounds were also evaluated from the point of view of their colour properties and structure. 相似文献
2.
Petra Šulcová Lucie Vitásková Miroslav Trojan 《Journal of Thermal Analysis and Calorimetry》2010,99(2):409-413
Compounds based on CeO2 were synthesized as high-temperature environment-friendly inorganic pigments with interesting hues. The pigments have been
synthesized by using the solid state reaction in the temperature range from 1,300 to 1,600 °C. The host lattice of these pigments
is CeO2 that is doped by terbium ions. The incorporation of doped ions provides interesting orange colours after application into
ceramic glaze. The goal was to develop conditions for the synthesis of these compounds and to determine the influence of calcination
temperature on their colouring effects. The simultaneous TG-DTA measurements were used for determination of the temperature
region of the pigment formation and thermal stability of pigments. The pigments were also evaluated from the standpoint of
their structure and particle sizes. 相似文献
3.
P. Šulcová 《Journal of Thermal Analysis and Calorimetry》2005,82(1):51-54
Summary The synthesis of new compounds based on the CeO2-PrO2-Nd2O3system, which can be used as pigments for colouring of ceramic glazes, is investigated in our laboratory. The optimum conditions
for the syntheses of these compounds have been estimated. The methods of thermal analysis provided first information about
the temperature region of the formation of the pigments investigated. The synthesis of these compounds was followed by thermal
analysis using STA 449/C Jupiter (Netzsch, Germany). 相似文献
4.
The synthesis of new compounds based on Bi2O3
is investigated because they can be used as new environmentally friendly inorganic
pigments. Chemical compounds of the (Bi2O3)1–x(Er2O3)x type were synthetized.
The host lattice of these pigments is Bi2O3 that is doped by Er3+
ions. The incorporation of doped ions provides interesting colours and contributes
to an increase in the thermal stability of these compounds. The simultaneous
TG-DTA measurements were used for determination of the temperature region
of the pigment formation and thermal stability of pigments. 相似文献
5.
Petra Šulcová Jan Večeřa Pavel Bystrzycki 《Journal of Thermal Analysis and Calorimetry》2012,108(2):525-529
New environmentally inorganic pigments based on Bi2O3 doped by metal ions, such as Zr4+ and Dy3+ have been developed and characterized using the methods thermal analysis, X-ray powder diffraction, and spectral reflectance
data. The compounds having formula Bi2−x
Dy
x/2Zr3x/8O3 (x = 0.2, 0.6, 1.0, and 1.2) were prepared by the solid state reaction. Methods of thermal analysis were used for determination
of the temperature region of the pigment formation and thermal stability of compounds. The incorporation of doped ions in
Bi2O3 changes the color from yellow to orange and also contributes to a growth of their thermal stability. This property gives
a direction for coloring ceramic glazes. 相似文献
6.
Žaneta Dohnalová Petra Šulcová Miroslav Trojan 《Journal of Thermal Analysis and Calorimetry》2010,101(3):973-978
The main aim of this work was to synthesize the magnesium orthostannate doped by terbium cations and tested whether these
materials can be used for colouring of the different materials, e.g. organic binder and ceramic glazes. Initial composition
of pigments was counted according the general formula 2MgO(1 − x)SnO2–xTbO2, where values of x varied from 0.1 to 0.5 in 0.1 steps. The simultaneous TG/DTA measurements of mixture containing tin oxide, magnesium carbonate
hydroxide and terbium oxide showed that the formation of a new compound started at temperature 1,029 °C, but single-phase
system was not prepared. Granulometric compositions of samples that were prepared by calcining at temperatures 1,300–1,400 °C
are characterized by values of median (d
50) in range 4–8 μm. The calcining temperature 1,500 °C caused the increase of the particle sizes at around 12 μm. The composition
of sample 2MgO–1.5SnO2–0.5TbO2 and heating temperature 1,500 °C are the most suitable conditions for preparation of colourfully interesting pigment that
can be recommended also for colouring of ceramic glazes. Especially, for colouring of decorative lead containing glaze G 07091
containing 5 wt% of PbO and 8 wt% of Al2O3. 相似文献
7.
Žaneta Dohnalová Petra Šulcová M. Trojan 《Journal of Thermal Analysis and Calorimetry》2008,93(3):857-861
Inorganic pigments containing lanthanides based on orthorhombic perovskite structure of CaSnO3 have been prepared by solid state reaction of CaCO3, SnO2 and lanthanide oxides (Tb4O7, Pr6O11, CeO2). The TG-DTA analysis indicates the formation of Ca-stannates around of temperature 1200°C, but from the pigmentary — application
point of view, it is better to synthesize the product at higher temperature (1400 or 1500°C). The resultant materials were
characterised by XRD, particle size distribution and measurement of colour properties. The doping of Ca-stannates by ions
of rare earth elements (Tb, Pr, Ce) brings the production of two-and three-phase systems. The most interesting colour properties
provided the stannate doped by ions of terbium and cerium and synthesized by heating at temperature 1400°C. The pigment has
reddish brown colour hue. 相似文献
8.
Fabiane Alexsandra Andrade de Jesus Ronaldo Santos da Silva Zélia Soares Macedo 《Journal of Thermal Analysis and Calorimetry》2010,100(2):537-541
Bismuth germanate ceramic powders were synthesized for the first time by the polymeric precursor method (Pechini’s method).
Differential thermal analysis and thermogravimetric techniques were used to study the decomposition of the resin precursor,
which indicated a suitable calcination temperature at 600 °C. It was observed that the mass loss occurs in two main stages
that are associated with two exothermic reactions. The crystalline phases of the powders were inspected by the X-ray diffraction
technique after thermal treatment between 300 and 600 °C. Single phase Bi4Ge3O12 ceramic bodies were obtained after sintering at 840 °C for 10 h. The sintered ceramics presented a luminescence band emission
centred at around 530 nm when excited with X-rays and UV radiation. 相似文献
9.
Lay Gaik Teoh 《Journal of Sol-Gel Science and Technology》2012,62(1):47-51
Mesoporous CeO2 and yttrium doped CeO2 (YDC) were prepared by a sol–gel process and characterized by a variety of techniques. XRD patterns showed that the undoped
and doped samples had a cubic fluorite structure. The grain size decreased from 24.8 to 6.1 nm at 500 °C for pure CeO2 and YDC, respectively. N2 adsorption–desorption isotherms showed that the samples possessed typical mesopore characteristics. The BET specific surface
area of the samples increased from 23.04 to 151.49 m2/g for 300 °C calcination after mesoporous CeO2 was doped with Y. It is found that the introduction of Y can inhibit the grain growth, and the presence of the pores also
can be related to this obstacle to grain growth. These results are of great significance for the control of porous microstructure,
crystallinity, and applications for the development of nanostructured mesoporous materials. 相似文献
10.
H. Nasser Á. Rédey Tatiana Yuzhakova J. Kovács 《Journal of Thermal Analysis and Calorimetry》2009,95(1):69-74
In order to explore the influence of CeO2 on the structure and surface characteristics of molybdena, an investigation was undertaken by using N2 adsorption (BET method), thermal analysis and in-situ diffuse reflectance infrared (DRIFT) techniques. In this work, the
Mo/CeO2 and Ce-Mo/Al2O3 samples were prepared by impregnation and co-precipitation methods with high Mo loadings. Combining the results one may notice
that the presence of ceria led to the increase of polymerized surface Mo species so as to forming Mo-O-Ce linkages besides
the formation of coupled O=Mo=O bonds indicative of polymeric MoO3.
From thermal analysis, it can be inferred that Mo/Al2O3 is the thermally most stable material in the temperature range used in the experiment (up to 900°C), whereas Ce-Mo/Al2O3 and Mo/CeO2 samples undergo morphological modifications above 700°C resulting in lattice defects, which motivate the mobility of Mo and
Ce ions and thus enhance the possibility of interaction between them. Additionally, their activity towards CO adsorption needs
reduced ceria and molybdena containing coordinatively unsaturated sites (CUS), oxygen vacancies and hydroxyl groups to form
various carbonate species. 相似文献
11.
Powders of composition Ni3(XO4)2 with X = P and V were synthesized by both the ceramic conventional and the Pechini-type in situ polymerizable complex (IPC)
method. The Pechini-type IPC technique produces these materials as single phases at reduced temperatures (750–810 °C) as opposed
to the conventional solid-state reaction methods in which processing temperatures higher than 800 °C are usually required
to obtain a single-phase of these materials. Reflections peaks of the samples obtained in both cases can be indexed well with
the standard patterns for Ni3(PO4)2 and Ni3(VO4)2 compounds. The lattice parameters of these materials were calculated by the Rietveld refinement method from X-ray diffraction
data (XRD). The average crystal size as well as the crystallinity and morphology of the powder samples were characterized
by scanning electron microscopy (SEM). The results show a clearly minor particle size by using the Pechini-IPC method than
the ceramic one. Moreover, the magnetic behaviour was studied on powered samples by using magnetic susceptibility data. 相似文献
12.
Žaneta Dohnalová Petra Šulcová M. Trojan 《Journal of Thermal Analysis and Calorimetry》2008,91(2):559-563
This work is focused on determination of the optimum firing temperature which leads to formation of the compounds LnFeO3 with good pigment-application properties (Ln=Gd, La, Yb, Tm, Lu). Based on results of thermal analysis the compounds were prepared by the solid-state reaction at temperature
900 and 1000°C. Colours of pigments vary depending on type of used lanthanoid (from light sienna to dark brown) and also on
the type of precursor. Generally, the compounds prepared from iron oxide have more interesting color properties. Colour of
these compounds is brighter and deeper. Increasing of the calcination temperature from 900 to 1000°C causes the darkening
of colour. The most problably, the darkening is connected with partial reduction of Fe3+ to Fe2+. 相似文献
13.
M. C. Navarro M. C. Lagarrigue J. M. De Paoli R. E. Carbonio M. I. Gómez 《Journal of Thermal Analysis and Calorimetry》2010,102(2):655-660
In order to investigate the formation of the multiferroic BiFeO3, the thermal decomposition of the inorganic complex Bismuth hexacyanoferrate (III) tetrahydrate, Bi[Fe(CN)6]·4H2O has been studied. The starting material and the decomposition products were characterized by IR spectroscopy, thermal analysis,
laboratory powder X-ray diffraction, and microscopic electron scanning. The crystal structures of these compounds were refined
by Rietveld analysis. BiFeO3 were synthesized by the decomposition thermal method at temperature as low as 600 °C. There is a clear dependence of the
type and amount of impurities that are present in the samples with the time and temperature of preparation. 相似文献
14.
Tao Yuan Zhonglei Wei Jing Yuan Longgang Yan Qingfang Liu Jianbo Wang 《Journal of Sol-Gel Science and Technology》2011,58(2):501-506
Nickel zinc ferrite (Ni0.4Zn0.6Fe2O4) films on Si (100) substrate were synthesized using a spin-coating method. The crystallinity of the Ni0.4Zn0.6Fe2O4 films with the thickness of about 386 nm became better as the annealing temperature increased. The films have smooth surface,
relatively good packing density and uniform thickness. The volatilization of Zn is serious at 900 °C. With the increase of
annealing temperature, the saturation magnetization M
s increases in the temperature ranging from 400 to 700 °C, however, decreases above 700 °C, and the coercivity H
c increases in the temperature range 400–800 °C, decreases above 800 °C. After annealed at 700 °C for 2 h in air with the heating
rate 2 °C/min, the film shows a maximum saturation magnetization M
s of 349 emu/cc and low coercivity H
c of 66 Oe. The M
s is higher than others which prepared by this method, however, the H
c is lower. The M
s of Ni0.4Zn0.6Fe2O4 films annealed at 700 °C increases with increasing annealing time and the H
c changes slightly. 相似文献
15.
The conductivity and transport number of oxygen ions of BiVO4-(5, 7, 10, 12) wt % V2O5 ceramic composites are measured using the four-probe and coulomb-volumetric methods, respectively, in the temperature range from 500 to 660°C. The phase transition of wetting of grain boundaries with eutectic melt at 640°C is discovered. It is shown that the grain boundary wetting significantly raises the ionic conductivity of composites. 相似文献
16.
Jitka Hreščak Barbara Malič Jena Cilenšek Andreja Benčan 《Journal of Thermal Analysis and Calorimetry》2017,127(1):129-136
The solid-state synthesis of undoped K0.5Na0.5NbO3 (KNN) and KNN doped with 1, 2 and 6 mol% Sr, from potassium, sodium and strontium carbonates with niobium pentoxide, was studied using thermal analysis and in situ high-temperature X-ray diffraction (HT-XRD). The thermogravimetry and the differential thermal analyses with evolved-gas analyses showed that the carbonates, which were previously reacted with the moisture in the air to form hydrogen carbonates, partly decomposed when heated to 200 °C. In the temperature interval where the reaction was observed, i.e., between 200 and 750 °C, all the samples exhibited the main mass loss in two steps. The first step starts at around 400 °C and finishes at 540 °C, and the second step has an onset at 540 °C and finishes with the end of the reaction between 630 and 675 °C, depending on the particle size distribution of the Nb2O5 precursor. According to the HT-XRD analysis, the perovskite phase is formed at 450 °C for all the samples, regardless of the Sr content. The formation of a polyniobate phase with a tetragonal tungsten bronze structure was detected by HT-XRD in the KNN with the largest amount of Sr dopant, i.e., 6 mol% of Sr, at 600 °C. 相似文献
17.
A. A. Shutilov G. A. Zenkovets S. V. Tsybulya V. Yu. Gavrilov G. N. Kryukova 《Kinetics and Catalysis》2012,53(3):409-418
The effect of the microstructure of titanium dioxide on the structure, thermal stability, and catalytic properties of supported CuO/TiO2 and CuO/(CeO2-TiO2) catalysts in CO oxidation was studied. The formation of a nanocrystalline structure was found in the CuO/TiO2 catalysts calcined at 500°C. This nanocrystalline structure consisted of aggregated fine anatase particles about 10 nm in size and interblock boundaries between them, in which Cu2+ ions were stabilized. Heat treatment of this catalyst at 700°C led to a change in its microstructure with the formation of fine CuO particles 2.5–3 nm in size, which were strongly bound to the surface of TiO2 (anatase) with a regular well-ordered crystal structure. In the CuO/(CeO2-TiO2) catalysts, the nanocrystalline structure of anatase was thermally more stable than in the CuO/TiO2 catalyst, and it persisted up to 700°C. The study of the catalytic properties of the resulting catalysts showed that the CuO/(CeO2-TiO2) catalysts with the nanocrystalline structure of anatase were characterized by the high-est activity in CO oxidation to CO2. 相似文献
18.
Mingquan Liu Xiangqian Shen Fuzhan Song Jun Xiang Ruijiang Liu 《Journal of Sol-Gel Science and Technology》2011,59(3):553-560
Sr0.8La0.2Zn0.2Fe11.8O19/poly(vinyl pyrrolidone) (PVP) composite fiber precursors were prepared by the sol–gel assisted electrospinning. Subsequently,
the M-type ferrite Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers with diameters about 120 nm were obtained by calcination of these precursors at different heat treatment conditions.
The precursor and resultant Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive
X-ray spectrometer and vibrating sample magnetometer. With the calcination temperature increased up to 1,000 °C for 2 h or
the holding time prolonged to 12 h at 900 °C, the Sr0.8La0.2Zn0.2Fe11.8O19 particles gradually grow into a hexagonal elongated plate-like morphology due to the dimensional control along the nanofiber
length. These elongated plate-like particles will be linked one by one to form the nanofiber with a necklace-like morphology.
The magnetic properties of the Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers are closely related to grain sizes, impurities and defects in the ferrite, which are influenced by the calcination
temperature, holding time and heating rate. After calcined at 900 °C for 12 h with a heating rate of 3 °C/min, the optimized
magnetic properties are achieved with the specific saturation magnetization 75.0 A m2 kg−1 and coercivity 426.3 kA m−1 for the Sr0.8La0.2Zn0.2Fe11.8O19 nanofibers. 相似文献
19.
Tatiana Nedoseykina Pavel Plyusnin Yuri Shubin Sergey Korenev 《Journal of Thermal Analysis and Calorimetry》2010,102(2):703-708
Thermolysis of double complex salt [Pd(NH3)4][AuCl4]2 has been studied in helium atmosphere from ambient to 350 °C. The XAFS of Pd K and Au L3 edges and thermogravimetry measurements have been carried out to characterize the intermediates and the final product. In
the temperature range 115–160 °C the complex is decomposed to form Pd(NH3)2Cl2 and AuCl4−x
N
x
species with x ranging from 2 to 3. Subsequent heating of the intermediate up to 300 °C leads to the total loss of NH3. The Au–Cl and Au–Au bonds form the local environment of Au at the stage of decomposition while only four chlorine atoms
are around Pd. At the temperature of 330 °C the Au and Pd nanoparticles as well as residues of palladium chloride are detected.
The final product consists of separated Au and Pd nanoparticles. 相似文献
20.
Rosa Maria Rojas K. Petrov G. Avdeev J. M. Amarilla L. Pascual J. M. Rojo 《Journal of Thermal Analysis and Calorimetry》2007,90(1):67-72
Chromium doped spinels LiCrYMn2−YO4 (0.2≤Y≤0.8) has been synthesized by the sucrose-aided combustion procedure. The thermal behaviour, phase homogeneity and structural
characteristics of the samples were studied by thermal analysis, coupled mass spectrometry, and room-and high-temperature
X-ray diffraction methods. It was found that the ‘as prepared’ samples contained residual organic impurities undetectable
for X-ray diffraction, that burn out completely at 400°C. Samples treated between 400 and 750°C are single phase spinels,
whose crystallites size increase from 10 to 50 nm on increasing the temperature. Cr-doping enhances the thermal stability
of the spinels, which augments on increasing the Cr content Y. The enhanced thermal stability of the spinels has been accounted
for based on the high excess stabilization energy of Cr3+ in octahedral ligand field. 相似文献