共查询到20条相似文献,搜索用时 31 毫秒
1.
O. N. Kondrat’eva A. I. Stognii N. N. Novitskii A. V. Bespalov O. L. Golikova G. E. Nikiforova M. N. Smirnova V. A. Ketsko 《Russian Journal of Inorganic Chemistry》2016,61(9):1080-1084
Mg(Fe0.8Ga0.2)2O4 films 340 nm thick were prepared by ion-beam sputtering on aluminasmoothed GaN substrates. Reactions that can occur between the components of heterostructure during its crystallization in the range 298.15–1273 K are analyzed. In order for Mg(Fe0.8Ga0.2)2O4 films to be continuous, their crystallization temperature should be lowered and alumina deposition—sputtering on GaN should be repeated several times. 相似文献
2.
M. N. Smirnova M. A. Kop’eva E. N. Beresnev L. V. Goeva N. P. Simonenko G. E. Nikiforova V. A. Ketsko 《Russian Journal of Inorganic Chemistry》2018,63(4):439-443
A powderlike material of composition MgFe1.6Ga0.4O4 was synthesized by gel combustion using a glycine–hexamethylenetetramine mixture. The gel produced by the synthesis was studied by thermal analysis (TGA/DSC) and IR spectroscopy. This mixture was shown to be efficient for obtaining homogeneous nanosized MgFe1.6Ga0.4O4. The morphology of the powders was characterized by scanning electron microscopy and X-ray powder diffraction analysis. 相似文献
3.
L. R. Gonsalves S. C. Mojumdar V. M. S. Verenkar 《Journal of Thermal Analysis and Calorimetry》2011,104(3):869-873
Cobalt zinc ferrite, Co0.8Zn0.2Fe2O4, nanoparticles have been synthesized via autocatalytic decomposition of the precursor, cobalt zinc ferrous fumarato hydrazinate.
The X-ray powder diffraction of the ‘as prepared’ oxide confirms the formation of single phase nanocrystalline cobalt zinc
ferrite nanoparticles. The thermal decomposition of the precursor has been studied by isothermal, thermogravimetric and differential
thermal analysis. The precursor has also been characterized by FTIR, and chemical analysis and its chemical composition has
been determined as Co0.8Zn0.2Fe2(C4H2O4)3·6N2H4. The Curie temperature of the ‘as-prepared oxide’ was determined by AC susceptibility measurements. 相似文献
4.
N. N. Gedam P. R. Padole S. K. Rithe G. N. Chaudhari 《Journal of Sol-Gel Science and Technology》2009,50(3):296-300
Thick film of nanocrystalline Co0.8Ni0.2Fe2O4 was obtained by sol–gel citrate method for gas sensing application. The synthesized powder was characterized by X-ray diffraction
(XRD) and transmission electron microscopy. The XRD pattern shows spinel type structure of Co0.8Ni0.2Fe2O4. XRD of Co0.8Ni0.2Fe2O4 revels formation of solid solution with average grain size of about 30 nm. From gas sensing properties it observed that nickel
doping improves the sensor response and selectivity towards ammonia gas and very low response to LPG, CO, and H2S at 280 °C. Furthermore, incorporation of Pd improves the sensor response and stability of ammonia gas and reduced the operating
temperature upto 210 °C. The sensor is a promising candidate for practical detector of ammonia. 相似文献
5.
Shiming Liu Xiaoliang Qian Jianzhong Xiao 《Journal of Sol-Gel Science and Technology》2007,44(3):187-193
Nano-crystalline La0.8Sr0.2Co0.5Fe0.5O3±δ powder has been successfully synthesized by microwave assisted sol–gel (MWSG) method. The decomposition and crystallization
behavior of the gel-precursor was studied by Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analysis.
From the result of FT-IR and X-ray diffraction patterns, it is found that a perovskite La0.8Sr0.2Co0.5Fe0.5O3±δ was formed by irradiating the precursor at 700 W for 3 min, but the well-crystalline perovskite La0.8Sr0.2Co0.5Fe0.5O3±δ was obtained at 700 W for 35 min. Morphological and specific area analysis of the powder were done by transmission electron
microscopy (TEM), scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET). The surface areas measured was 38.9 m2/g and the grain size was ∼23 nm. Electrochemical properties of pure LSCF cathode on YSZ electrolyte at intermediate temperatures
were investigated by using AC impedance analyzer, which shows a low area specific resistance (0.077 Ω cm2 at 1073 K and 0.672 Ω cm2 at 953 K). Moreover, the synthesis period of 20 h usually observed for conventional heating mode is reduced to a few minutes.
Thus, the MWSG method is proved to be a novel, extremely facile, time-saving and energy-efficient route to synthesize LSCF
powders. 相似文献
6.
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
7.
M. N. Smirnova A. A. Geras’kin A. I. Stognii O. L. Golikova A. V. Bespalov A. V. Trukhanov M. A. Kop’eva E. N. Beresnev V. A. Ketsko 《Russian Journal of Inorganic Chemistry》2014,59(7):778-782
The results of analysis of conceivable interactions between film and substrate materials during crystallization of Mg(Fe0.8Ga0.2)2O4-δ films with SiO2 and TiO2 buffer layers on silicon are reported. The calculated data are compared with the physicochemical parameters of Mg(Fe0.8Ga0.2)2O4-δ/Si, Mg(Fe0.8Ga0.2)2O4-δ/TiO2/Si, and Mg(Fe0.8Ga0.2)2O4-δ/SiO2/Si film heterostructures. 相似文献
8.
Xiangqian Peng Wei Zhang Ligang Gai Haihui Jiang Yan Tian 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(8):1656-1664
Thiol-functionalized Fe3O4/SiO2 microspheres (Fe3O4/SiO2-SH) with high saturation magnetization (69.3 emu g–1), superparamagnetism, and good dispersibility have been prepared by an ethylene glycol reduction method in combination with a modified Stöber method. The as-prepared composite magnetic spheres are characterized with fourier transform infrared spectroscopy (FT-IR), zeta potential, X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference magnetometer, and tested in separation of Au(III) ions from aqueous solutions. The data for Au(III) adsorption on Fe3O4/SiO2-SH are analyzed with the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherm models, and the pseudo-first-order, pseudo-second-order, and intraparticle diffusion kinetics models. The adsorption behaviors of Au(III) on Fe3O4/SiO2-SH follow the Langmuir isotherm model, and the adsorption process conforms to the pseudo-second-order kinetic model. The maximum adsorption capacity of Au(III) on Fe3O4/SiO2-SH is 43.7 mg g–1. Acetate anions play an important role yet Cu(II) ions have little interference in the adsorption of Au(III) on the adsorbent. A satisfactory recovery percentage of 89.5% is acquired by using an eluent with 1 M thiourea and 5% HCl, although thiols have a high affinity to Au(III) ions based on the hard-soft acid-base (HSAB) theory by Pearson. 相似文献
9.
Marcela Stoia C. Caizer M. Stefanescu P. Barvinschi I. Julean 《Journal of Thermal Analysis and Calorimetry》2007,88(1):193-200
This article presents the results
of our investigation on the obtaining of Ni0.65Zn0.35Fe2O4 ferrite nanoparticles embedded in a SiO2 matrix using
a modified sol–gel synthesis method, starting from tetraethylorthosilicate
(TEOS), metal (FeIII,NiII,ZnII)
nitrates and ethylene glycol (EG). This method consists in the formation of
carboxylate type complexes, inside the silica matrix, used as forerunners
for the ferrite/silica nanocomposites. We prepared gels with different compositions,
in order to obtain, through a suitable thermal treatment, the nanocomposites
(Ni0.65Zn0.35Fe2O4)x–(SiO2)100–x (where x=10,
20, 30, 40, 50, 60 mass%). The synthesized gels were studied by differential
thermal analysis (DTA), thermogravimetry (TG) and FTIR spectroscopy.
The formation of Ni–Zn ferrite in the silica matrix and the behavior
in an external magnetic field were studied by X-ray diffraction (XRD) and
quasi-static magnetic measurements (50 Hz). 相似文献
10.
Fe3O4 nanorods and Fe2O3 nanowires have been synthesized through a simple thermal oxide reaction of Fe with C2H2O4 solution at 200–600°C for 1 h in the air. The morphology and structure of Fe3O4 nanorods and Fe2O3 nanowires were detected with powder X-ray diffraction, scanning electron microscopy and transmission electron microscopy.
The influence of temperature on the morphology development was experimentally investigated. The results show that the polycrystals
Fe3O4 nanorods with cubic structure and the average diameter of 0.5–0.8 μm grow after reaction at 200–500°C for 1 h in the air.
When the temperature was 600°C, the samples completely became Fe2O3 nanowires with hexagonal structure. It was found that C2H2O4 molecules had a significant effect on the formation of Fe3O4 nanorods. A possible mechanism was also proposed to account for the growth of these Fe3O4 nanorods.
Supported by the Fund of Weinan Teacher’s University (Grant No. 08YKZ008), the National Natural Science Foundation of China
(Grant No. 20573072) and the Doctoral Fund of Ministry of Education of China (Grant No. 20060718010) 相似文献
11.
Irena Szczygieł Aleksandra Matraszek Teresa Znamierowska 《Journal of Thermal Analysis and Calorimetry》2008,93(3):671-676
Ce2O3-K2O-P2O5 ternary system has been investigated by thermoanalytical methods (DTA, DSC), powder X-ray diffraction, XPS and IR spectroscopy.
The existence of three double potassium-cerium(III) phosphates has been confirmed and a new binary phosphate K4Ce2P4O15 has been found. Phase diagram and isothermal section at room temperature of the system Ce2O3-K2O-P2O5 have been presented. 相似文献
12.
Chiwei Wang Xiaoling Ma Jinguo Cheng Jutang Sun Yunhong Zhou 《Journal of Solid State Electrochemistry》2007,11(3):361-364
LiNi0.8Co0.2O2 and Ca-doped LiNi0.8Co0.2O2 cathode materials have been synthesized via a rheological phase reaction method. X-ray diffraction studies show that the
Ca-doped material, and also the discharged electrode, maintains a hexagonal structure even when cycled in the range of 3.0–4.35 V
(vs Li+/Li) after 100 cycles. Electrochemical tests show that Ca doping significantly improves the reversible capacity and cyclability.
The improvement is attributed to the formation of defects caused by the partial occupancy of Ca2+ ions in lithium lattice sites, which reduce the resistance and thus improve the electrochemical properties. 相似文献
13.
L. P. Ogorodova I. A. Kiseleva E. N. Korytkova T. P. Maslennikova V. V. Gusarov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(1):44-47
Nanotubular (Mg,Fe2+,Fe3+)3Si2O5(OH)4 hydrosilicates with a chrysotile structure were synthesized under hydrothermal conditions. The phases prepared were studied
thermochemically on a high-temperature Tian-Calvet microcalorimeter by solution calorimetry. The standard enthalpies of formation
of magnesium-iron nanotubular hydrosilicates were determined. The formation of iron-containing nanotubes was shown to be lass
favorable energetically than the formation of magnesium nanotubes. 相似文献
14.
M. G. Ivanov A. N. Shmakov V. A. Drebushchak O. Yu. Podyacheva 《Journal of Thermal Analysis and Calorimetry》2010,100(1):79-82
Perovskite SrCo0.6Fe0.2Nb0.2O3-z attracts attention as a promising material with high oxygen conductivity. The sample was investigated by means of high-temperature
X-ray powder diffraction and thermogravimetry. Phase transition was detected near 400 °C and accompanied with significant
mass loss. The phase transition affects oxygen mobility, important for the synthesis of oxygen permeable membranes. The unit
cell parameters are proved to change with temperature after two effects (1) reversible conventional thermal expansion and
(2) irreversible contraction-expansion due to the changes in the oxygen content. In situ high-temperature X-ray diffraction
experiments allowed us to separate the contributions and to measure them as a function of temperature. 相似文献
15.
A. A. Geras’kin A. I. Stognii N. N. Novitskii A. V. Trukhanov A. V. Bespalov O. L. Golikova E. N. Beresnev M. A. Kop’eva V. A. Ketsko 《Russian Journal of Inorganic Chemistry》2014,59(3):183-186
Conditions of the synthesis of magnetic semiconductor films of composition Mg(Fe0.8Ga0.2)2O4?δ on silicon have been optimized. As the barrier layer, which prevents the interaction between the film and the substrate during high-temperature crystallization of the films, a film of nanosized silicon dioxide was used. This, together with a high homogeneity of the composition of the target, allowed us to obtain Mg(Fe0.8Ga0.2)2O4?δ films on silicon characterized by the saturation magnetization (37 A m2/kg) that noticeably exceeds that for the volumetric analog (28 A m2/kg). 相似文献
16.
Li Wang Zebin Yu Zhenbo Peng Ying Chen Guoliang Xiang Qing Liu Yuxin Liu Dongmei Chen 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(4):777-782
We proposed here a new process coupling dielectric barrier discharge (DBD) plasma with magnetic photocatalytic material nanoparticles for improving yield in DBD degradation of methyl orange (MO). TiO2 doped Fe3O4 (TiO2/Fe3O4) was prepared by the sol-gel method and used as a new type of magnetic photocatalyst in DBD system. It was found that the introduction of TiO2/Fe3O4 in DBD system could effectively make use of the energy generated in DBD process and improve hydroxyl radical contributed by the main surface Fenton reaction, photocatalytic reaction and catalytic decomposition of dissolved ozone. Most part of MO (88%) was degraded during 30 min at peak voltage of 13 kV and TiO2/Fe3O4 load of 100 mg/L, with a rate constant of 0.0731 min?1 and a degradation yield of 7.23 g/(kW h). The coupled system showed higher degradation efficiency for MO removal. 相似文献
17.
Stabilization of oil-in-water Pickering emulsions with SiO2 and Fe3O4 nanoparticles has been studied. Emulsions containing three-dimensional gel networks formed by aggregated nanoparticles in the dispersion media have been shown to be stable with respect to flocculation, coalescence, and creaming. Concentration ranges in which emulsions are kinetically stable have been determined. Stabilization with mixed Ludox HS-30 and Ludox CL SiO2 nanoparticles leads to the formation of stable emulsions at a weight ratio between the nanoparticles equal to 2 and pH 6.7. In the case of stabilization with Ludox CL and Fe3O4 nanoparticles, systems resistant to aggregation and sedimentation are obtained at pH 8. The use of mixed Ludox HS-30 and Fe3O4 nanoparticles has not resulted in the formation of emulsions stable with respect to creaming, with such emulsions appearing to be resistant only to coalescence at pH 2–6. 相似文献
18.
L. F. Brum Malta Marta Eloisa Medeiros 《Journal of Thermal Analysis and Calorimetry》2005,81(1):149-152
Summary This work reports the room-temperature stabilization of the Bi4V2-xFexIIO11-1.5x γ ‘ phase, a promising ionic conductive material that finds application in solid oxide fuel cell and oxygen sensor devices. The Fe(II) cation proved to be a better stabilizer than Fe(III), which was previously used, since a lower substitution degree of V5+ is needed for the former. Powder X-ray diffraction, Fourier-transform infrared spectroscopy and differential scanning calorimetry were used in these experiments. 相似文献
19.
A. S. Kalyuzhnaya A. M. Abakumov M. G. Rozova H. D’Hondt J. Hadermann E. V. Antipov 《Russian Chemical Bulletin》2010,59(4):706-711
The complex oxide Ca7Mn2.14Ga5.86O17.93 was synthesized by the solid-state reaction in a sealed evacuated quartz tube at 1000 °C. Its crystal structure was determined
by electron diffraction and X-ray powder diffraction. The structure can be represented as a tetrahedral framework, viz., the
polyanion [(Mn0.285Ga0.715)15O29.86]19- stabilized by the incorporated cation [Ca14GaO6]19+. The polycation consists of the GaO6 octahedra surrounded by the Ca atoms, which are arranged to form a cube capped at all places. The tetrahedral framework is
partially disordered due to the presence of tetrahedra with two possible orientations in the positions (0, 0, 0) and (x, x,
x) with x ≈ 0.15 and 0.17. The relationship between the Ca7Mn2.14Ga5.86O17.93 structures and related ordered phases with the symmetry F23, as well as the influence of the oxygen content on the ordering
in the tetrahedral framework, are discussed. 相似文献
20.
T. I. Chupakhina N. V. Mel’nikova E. A. Yakovleva Yu. A. Nikitina 《Russian Journal of Inorganic Chemistry》2018,63(2):141-148
New solid solutions La1.8Sr0.2Ni0.8M0.2O4 (M = Fe, Co, or Cu) have been prepared, and their crystal- chemical characteristics and electric properties studied. The studied materials have been shown to have activation-time conductivity. Structural distortions have been found to affect the dielectric properties of ceramic samples. La1.8Sr0.2Ni0.8M0.2O4 is observed to have the greatest distortion of АО9 coordination polyhedra and a higher dielectric constant. 相似文献