基于密度泛函理论的高熵氧化物(MgCoNiCuZn)O稳定性研究

Study on the Stability of High-Entropy Oxides(MgCoNiCuZn) O Based on Density Functional Theory

高熵氧化物(MgCoNiCuZn)O是近年来发展起来的新兴高熵陶瓷材料,是一种单相固溶体,具有面心立方结构,由于构成该化合物的原子呈局域无序状,使得其在热学、电学方面展示出优异的特性,具有较大的介电常数、良好的导电性能,在电化学储能材料及电极材料方面有着较好的应用前景,其稳定性对于热电性能有重要的影响。文章采用特殊准随机结构(Special quasirandom structures,SQS)模拟建立结构模型,采用基于密度泛函理论以及准谐近似德拜-格林乃森Debye-Grüneise模型的从头算方法,对该氧化物(MgCoNiCuZn)O材料的稳定性进行了研究。

High-entropy oxide(MgCoNiCuZn)O is a new high entropy ceramic material developed in recent years. It is a single-phase solid solution with face centered cubic structure. Because the atoms constituting the compound are locally disordered, it shows excellent characteristics in thermal and electrical aspects, has large dielectric constant and good conductivity, and has a good application prospect in electrochemical energy storage materials and electrode materials. Its stability has an important influence on the thermoelectric performance.In this paper, the special quasi random structures(SQS) are used to simulate and establish the structural model. The stability of the oxide(MgCoNiCuZn)O material was studied by ab initio calculation method based on density functional theory and Quasi-harmonic approximate Debye-Grüneise model.