Modeling, Development and Creation of Ferroactive Materials Based on Multicomponent Complex Oxide Systems

Author(s):  
K.P. Andryuishin ◽  
◽  
I.N. Andryushina ◽  
I.A. Verbenko ◽  
S.I. Dudkina ◽  
...  
2021 ◽  
Vol 316 ◽  
pp. 105-109
Author(s):  
Evgeny A. Kirichenko ◽  
Pavel G. Chigrin ◽  
Anton A. Gnidenko

YFeO3-δ (δ = 0.26) and LaFeO3-δ (δ = 0.5) perovskites with a high specific surface and oxygen non-stoichiometry was firstly synthesized by pyrolysis of polymer-salt compositions. It was shown that the catalytic oxidation of carbon in the presence of these complex oxide systems proceeds in the range of 400 - 700 °С, with a maximum temperature at 556 °С for YFeO3-δ; and 380 - 620 °С ,with a maximum temperature at 501 °С for LaFeO3-δ, in one-stage mode for both. By means of thermal analysis and diffractometry, it was shown that there is no contribution to the soot oxidation mechanism by cyclic perovskite surface transformations, due to the reduction of metal oxides by the soot and their subsequent reoxidation. It has been established that the basis of the catalytic reaction mechanism for both perovskites is the presence of oxygen vacancies on the surface of complex oxides.


2003 ◽  
Vol 76 (10) ◽  
pp. 1564-1567 ◽  
Author(s):  
V. A. Popov ◽  
S. I. Lopatin ◽  
L. Sh. Tsemekhman ◽  
L. A. Pavlinova ◽  
S. P. Kormilitsyn ◽  
...  
Keyword(s):  

Author(s):  
A. Pilipenko ◽  
I. Fesych ◽  
S. Nedilko ◽  
A. Dzyazko

With the help of sol-gel technology was obtained superconducting compound number YxBax+nCu2x+nOδ (x=1, n=1; x=2, n=3; x=3, n=2) with submicron size particles. As a gel maker in these systems was used citric acid monohydrate. An extensive scheme fusion technology was shown. The process described synthesis using thermal, infrared spectroscopic analysis and scanning electron microscopy. There are some aggregations of microparticles mostly for the phases that are synthesized at higher temperatures. Due to Thermal Analysis of modes were optimized heat treatment samples. According to IR spectroscopy were controlled processes of decomposition of the charge and the formation of the superconducting phase. It was grounded the choice of analysis methods for the starting compounds and the present calculation algorithm for this synthesis. Studies have shown that even at the beginning of the synthesis batch contained no impurity compound allowing argued that the sol-gel synthesis is a promising method that provides high homogeneity of the material the early stages of the synthesis and enables lower temperature and a subsequent heat treatment. The results of electron microscopy showed that due to the relatively low temperature of synthesis occurs the formation of submicron sized particles, while solid-phase techniques facilitate rapid crystal growth due to the formation of liquid phases at high temperature. The principles and ideas described in this paper can be adapted to more complex oxide systems. Thus, in this paper describes how you can achieve chemical homogeneity at the molecular level in multicomponent systems YxBax+nCu2x+nOδ (x=1, n=1; x=2, n=3; x=3, n=2) using sol-gel technology.


2020 ◽  
Author(s):  
Nassar Doudin ◽  
Gregory Collinge ◽  
Pradeep Kumar Gurunathan ◽  
Mal Soon Lee ◽  
Vassiliki-Alexandra Glezakou ◽  
...  

<p>Complex oxide systems with hierarchical order are of critical importance in material science and catalysis. Despite their immense potential, their design and synthesis are rather difficult. In this study we demonstrate how the deposition of small oligomeric (MoO<sub>3</sub>)<sub>1-6</sub> clusters, which can be formed by the sublimation of MoO<sub>3</sub> powders, leads to the formation of locally ordered layers of (MoO<sub>3</sub>)<sub>1</sub> monomers on anatase TiO<sub>2</sub>(101). Using both high-resolution imaging and theoretical calculations, we show that at room temperature, such oligomers undergo spontaneous dissociation to their monomeric units. In initial stages of the deposition, this is reflected by the observation of one to six neighboring (MoO<sub>3</sub>)<sub>1</sub> monomers that parallel the size distribution of the oligomers. A transient mobility of such oligomers on both bare TiO<sub>2</sub>(101) and (MoO<sub>3</sub>)<sub>1</sub> covered areas is key to the formation of a complete layer with a saturation coverage of one (MoO<sub>3</sub>)<sub>1</sub> per two undercoordinated surface Ti sites. We further show that such layers are stable to 500 K, making them highly suitable for a broad range of applications. </p>


2021 ◽  
Vol 47 (5) ◽  
pp. 489-495
Author(s):  
A. F. Dresvyannikov ◽  
E. V. Petrova ◽  
A. N. Akhmetova ◽  
L. I. Kashfrazieva ◽  
I. D. Tverdov
Keyword(s):  

1963 ◽  
Vol 16 (10) ◽  
pp. 1060-1061 ◽  
Author(s):  
D. M. Chackraburtty ◽  
N. C. Jayadevan ◽  
C. K. Sivaramakrishan
Keyword(s):  

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