Zhang Junzhan, Liu Shangyi, Tian Zhifeng, Zhang Ying, Shi Zongmo
College of Materials Science and Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Shaanxi Key Laboratory of Nano Materials and Technology, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Materials (Basel). 2023 Mar 9;16(6):2214. doi: 10.3390/ma16062214.
High entropy perovskite oxides (HEPOs) were a class of advanced ceramic materials, which had attracted much scientific attention in recent years. However, the effect of factors affecting the phase stability of high entropy perovskite oxides was still controversial. Herein, 17 kinds of A-site HEPOs were synthesized by solid-state methods, and several criteria for the formation of HEPOs and phase stability were investigated. Single-phase solid solutions were synthesized in 12 kinds of subsystems. The results show that the phase stability of a single-phase solid solution was affected by the size disorder and configurational entropy. The electronegativity difference was the key parameter to predict the evolution of the cubic/tetragonal phase, rather than the tolerance factor. Cubic HEPOs were easily formed when the electronegativity difference was <0.4, while the tetragonal HEPOs were easily formed when the electronegativity difference was ≥0.4. This study can further broaden the family of HEPOs and is expected to design the phase stability of HEPOs through electronegativity difference.
高熵钙钛矿氧化物（HEPOs）是一类先进的陶瓷材料，近年来受到了诸多科学关注。然而，影响高熵钙钛矿氧化物相稳定性的因素的作用仍存在争议。在此，通过固态法合成了17种A位高熵钙钛矿氧化物，并研究了高熵钙钛矿氧化物形成和相稳定性的若干准则。在12种子系统中合成了单相固溶体。结果表明，单相固溶体的相稳定性受尺寸无序和组态熵的影响。电负性差是预测立方/四方相演变的关键参数，而非容差因子。当电负性差<0.4时，立方高熵钙钛矿氧化物易于形成，而当电负性差≥0.4时，四方高熵钙钛矿氧化物易于形成。本研究可进一步拓宽高熵钙钛矿氧化物家族，并有望通过电负性差设计高熵钙钛矿氧化物的相稳定性。
