Abstract

The oxygen diffusion has been simulated by the molecular dynamics method in the solid solutions of PrBaCo₂O_5.5-based double perovskites: PrBa_0.5Sr_0.5Co₂O_5.5 with random substitution of half of Ba atoms by Sr atoms, PrBa_0.5Sr_0.5CoFeO_5.5 with random substitution Ba → Sr and Co → Fe, PrBa_0.5Sr_0.5CoCuO_5.5 with random substitution Ba → Sr and Co → Cu, and PrBa_0.5Sr_0.5CuFeO_5.5 with random substitution Ba → Sr and random substitution of Co atoms by Fe and Cu atoms. It is shown that, varying the oxygen nonstoichiometry and/or chemical composition of solid solutions based on PrBa_0.5Sr_0.5Co₂O_5.5, one can significantly change the coefficient of thermal expansion of the materials. It is established for the first time that the maximum difference between the mobilities of oxygen atoms of different types observed in PrBa_0.5Sr_0.5Co₂O_5.5 significantly decreases at partial substitutions of cobalt by iron and copper. In the PrBa_0.5Sr_0.5CuFeO_5.5 solid solution, the oxygen atom mobility in the (Cu,Fe)–O layers becomes somewhat higher than that in the Pr–O layers.

中文翻译：

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基于PrBaCo 2 O 5.5的钙钛矿固溶体结构与输运性质的分子动力学模拟。

摘要

通过分子动力学方法在基于PrBaCo ₂ O _5.5的双钙钛矿固溶体中模拟了氧的扩散：PrBa _0.5 Sr _0.5 Co ₂ O _5.5，其中Ba原子的一半被Sr原子随机取代，PrBa _0.5 Sr _0.5 CoFeO _5.5随机取代Ba→Sr和Co→Fe，PrBa _0.5 Sr _0.5 CoCuO _5.5随机取代Ba→Sr和Co→Cu，PrBa _0.5 Sr _0.5 CuFeO _5.5Ba→Sr随机取代，Fe和Cu原子随机取代Co原子。结果表明，基于PrBa _0.5 Sr _0.5 Co ₂ O _5.5改变固溶体的氧非化学计量和/或化学组成，可以显着改变材料的热膨胀系数。首次确定在铁和铜部分取代钴时，在PrBa _0.5 Sr _0.5 Co ₂ O _5.5中观察到的不同类型氧原子迁移率之间的最大差异显着降低。在PrBa _0.5 Sr _0.5 CuFeO _5.5中 在固溶体中，（Cu，Fe）–O层中的氧原子迁移率变得略高于Pr–O层中的氧原子迁移率。