HfO_2铁电相与四方相转变关系的第一性原理研究  

First principle study of the transformation relationship between HfO_2 ferroelectric and tetragonal phases

作　　者：叶飞[1,2] 肖海珠[1] 周大雨[1,2] 

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116024 [2]大连理工大学三束材料改性教育部重点实验室,辽宁大连116024

出　　处：《功能材料》2014年第16期16070-16073,共4页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51272034)

摘　　要：基于密度泛函理论的缀加平面波方法计算了HfO2的正交相Pca21和四方相P42/nmc,其中正交相具有铁电性质。计算结果表明,在晶体结构方面,HfO2正交相和四方相都具有类萤石结构特征,并且从四方相P42/nmc到正交相Pca21的转变过程中单胞变形<3.75%;在电子结构方面,通过四方相到正交相的结构转变,Hf的5d和O的2p、2s的杂化效应增强,同时这些电子态向低能移动,使正交相的相对能量低于四方相。这些研究结果证实了HfO2具有铁电性质的Pca21正交相是一种稳定的相结构,并解释了从P42/nmc四方相到Pca21正交相的转变关系。The Pca21 orthogonal phase with ferroelectric property and P42/nmc tetragonal phase of HfO2 have been studied using the augmented plane wave within density functional theory in this work.It has been found out that in the case of the crystal structures,both the ferroelectric phase and the tetragonal phase can be regar-ded as fluorite-related structure,and the deformation of the unit cells during transformation from the tetragonal phase to the ferroelectric phase was less than 3.75%;in the case of the electronic structures,the hybridization of Hf 5d and O 2p,2s was enhanced by the transformation from the tetragonal phase to the ferroelectric phase, and the electron states shift to lower energy,which lead to a lower lattice energy of the ferroelectric phase. These results have confirmed that the Pca21 orthogonal phase with ferroelectric property was a stable phase, and provided further insight into the transformation relationship between the ferroelectric phase and the tetra-gonal phase.

关 键 词：HFO2 密度泛函理论 铁电相 电子结构 

分 类 号：TM221[一般工业技术—材料科学与工程]