Abstract

The change of the oxygen equilibrium partial pressure in the gas phase makes it possible to identify the synthesis conditions and operating modes of oxide materials. The effect of oxygen pressure on heterogeneous equilibria in the R–Mn–O (R = Y, Ho–Lu) systems was studied by a batch method during thermal dissociation of RMn₂O₅ and RMnO₃ manganites. The reduction sequence of oxides was elucidated. The temperature-dependent equilibrium oxygen pressure was determined in the range 973–1220 K for monovariant equilibria of RMn₂O₅ and RMnO₃ reduction, and the thermodynamic functions of formation from elements were calculated for the manganites. The thermal stability of RMn₂O₅ and RMnO₃ was determined as dependent on the ionic radius and the number of unpaired 4f electrons of the lanthanide.

中文翻译：

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氧气压力对 R-Mn-O (R = Y, Ho-Lu) R-Mn-O (R = Y, Ho-Lu) 复合氧化物体系中非均相平衡的影响

摘要

气相中氧平衡分压的变化使得确定氧化物材料的合成条件和操作模式成为可能。_{在RMn 2} O ₅和RMnO ₃锰酸盐热解过程中，通过间歇法研究了氧气压力对R-Mn-O（R = Y，Ho-Lu）体系中非均相平衡的影响。阐明了氧化物的还原顺序。对于 RMn ₂ O ₅和 RMnO ₃还原的单变量平衡，温度相关的平衡氧压力在 973-1220 K 范围内确定，并且计算了锰矿的元素形成的热力学函数。RMn _{2的热稳定性}O ₅和RMnO ₃被确定为取决于离子半径和镧系元素的未配对4 f电子的数量。