Thermal analysis of transition metal and rare earth oxide system-gas interactions by a solid electrolyte-based coulometric technique
Thermal analysis of transition metal and rare earth oxide system-gas interactions by a solid electrolyte-based coulometric technique
复制标题
采用基于固体电解质的库仑技术对过渡金属和稀土氧化物体系-气体相互作用进行热分析
DOI：
10.1007/bf01983677
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
N. Trofimenko
中科院分区：
文献类型：
--
作者：
K. Teske;H. Ullmann;N. Trofimenko
用固体电解质库仑法（SEC）在载气模式下研究了过渡金属和稀土氧化物体系在氧势控制气氛中的氧化还原行为，获得了有关氧化学计量范围、混合氧化物相的p-T-x图氧交换和相变的动力学。SEC和电导率测量的直接耦合提供了有关缺氧和电导率之间关系的进一步信息，在萤石型相PrO2−x、Ce0.8Pr0.2Oy−x和Ce0.8Sr0.08Pr0.12Oy−x中，Pr的较高氧化态稳定，电导率按此顺序增加。钙钛矿型相Sr 1 − yCeyFeO 3 −x显示出跃迁和第二相，反映在这种物质的程序升温光谱中。随着氧分压的增加，Sr0.9Ce0.1FeO3−x的电导率从n型转变为顶型。
The oxidation-reduction behaviour of transition metal and rare earth oxide systems in oxygen potential controlled atmospheres was investigated by means of a solid electrolyte-based coulometric technique (SEC) in carrier gas mode to obtain information concerning the extent of oxygen stoichiometry, thep-T-x diagram of any mixed oxide phase, the kinetics of the oxygen exchange and the phase transitions.The direct coupling of SEC and electrical conductivity measurements provides further information about the relationship between oxygen deficiency and conductivity, especially as concerns the oxygen mobility and the transition from ionic to mixed ionic/electronic conductivity in any system.In the fluorite-type phases PrO2−x, Ce0.8Pr0.2Oy−x and Ce0.8Sr0.08Pr0.12Oy−x, the higher oxidation state of Pr is stabilized and the electrical conductivity increases in this sequence. The perovskite-type phase Sr1−yCeyFeO3−x, shows transitions and a second phase reflected in the temperature-programmed spectrum of this substance. The electrical conductivity of Sr0.9Ce0.1FeO3−x changes fromn-type top-type with increasing oxygen pressure.