Perovskite‐like oxides AB′_1/2B′′_1/2O₃ with two different cations in the B‐sublattice may experience cation order–disorder phase transitions. In many cases the degree of cation ordering can be varied by suitable synthesis conditions or subsequent sample treatment, which has a fundamental impact on the physical properties of such compounds. Therefore, understanding the mechanism of cation order–disorder phase transition and estimation of the phase transition temperature is of paramount importance for tuning of properties of such double perovskites. In this work, based on the earlier proposed cation–anion elastic bonds model, a theory of order–disorder phase transitions of B‐cations in AB′_1/2B′′_1/2O₃ perovskites is presented, which allows reliable estimation of the phase transition temperatures and of the reduced lattice constants of such double perovskites.

中文翻译：

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AB'1 / 2B''1 / 2O3钙钛矿中B阳离子的有序无序相变理论。

钙钛矿型氧化物AB ' _1/2乙'' _1/2 ö ₃与在两个不同的阳离子乙-sublattice可能会遇到阳离子有序-无序相变。在许多情况下，阳离子的有序度可以通过合适的合成条件或后续的样品处理来改变，这对此类化合物的物理性质具有根本性的影响。因此，了解阳离子有序-无序相变的机理和估算相变温度对于调节这类双钙钛矿的性能至关重要。在这项工作中，基于较早提出的阳离子-阴离子弹性键模型，B的有序-无序相变理论在-cations AB ' _1/2乙'' _1/2 ö ₃钙钛矿被呈现，这允许相变温度的和这样的双钙钛矿的减小的晶格常数的可靠估计。