Vyacheslav A. Dudnikov , Yuri S. Orlov , Leonid A. Solovyov , Sergey N. Vereshchagin , Yuri N. Ustyuzhanin , Sergey M. Zharkov , Galina M. Zeer , Andrey A. Borus , Vitaly S. Bondarev , Sergey G. Ovchinnikov
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引用次数: 0
Abstract
Background:
Crystal structure of rare-earth LaCoO3 cobalt oxide subjected to high energy mechanical activation has been studied. In the temperature range of 300–800 K, the electrical conductivity and Seebeck coefficient were measured. Thermal conductivity was measured at 300–480 K.
Methods:
Comparative analysis of thermoelectric properties of the samples prepared by standard solid-state reaction and using high-energy mechanical activation was carried out.
Findings:
It was found that the experimental X-ray diffraction patterns are best described within the model that allows the coexistence of two domains in samples with the same crystal symmetry, but different lattice a and c parameters. The percentage ratio of these domains in the samples depends significantly on the size of the initial particles in the solid-state synthesis reaction and the annealing temperature. Mechanical activation and increase of synthesis temperature result in change of Seebeck coefficient sign and significant decrease of electrical resistivity. The Seebeck coefficient of non-activated samples takes positive values over the entire temperature range and decreases monotonically with increasing temperature, in contrast to mechanically activated samples exhibiting ambipolar behavior.
背景:研究了受高能机械活化的稀土 LaCoO3 氧化钴的晶体结构。在 300-800 K 的温度范围内,测量了电导率和塞贝克系数。研究结果:研究发现,实验 X 射线衍射图样在允许两个畴共存于具有相同晶体对称性但不同晶格 a 和 c 参数的样品中的模型中得到了最好的描述。这些畴在样品中的比例在很大程度上取决于固态合成反应中初始粒子的大小和退火温度。机械活化和合成温度的升高会导致塞贝克系数符号的改变和电阻率的显著下降。未活化样品的塞贝克系数在整个温度范围内都是正值,并随着温度的升高而单调降低,而机械活化样品则表现出伏极性。
期刊介绍:
Journal of the Taiwan Institute of Chemical Engineers (formerly known as Journal of the Chinese Institute of Chemical Engineers) publishes original works, from fundamental principles to practical applications, in the broad field of chemical engineering with special focus on three aspects: Chemical and Biomolecular Science and Technology, Energy and Environmental Science and Technology, and Materials Science and Technology. Authors should choose for their manuscript an appropriate aspect section and a few related classifications when submitting to the journal online.