Dynamical and dielectric properties of MP2O7 (M = Ti, Zr, and Hf): A first-principles investigation
Dynamical and dielectric properties of MP2O7 (M = Ti, Zr, and Hf): A first-principles investigation
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DOI：
10.1016/j.commatsci.2014.07.054
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发表时间：
2014-12
影响因子：
3.3
通讯作者：
Huimin Xiang;Zhi-hai Feng;Yanchun Zhou
中科院分区：
文献类型：
--
作者：
Huimin Xiang;Zhi-hai Feng;Yanchun Zhou
对MP2 O7（M = Ti、Zr和Hf）的结构和振动性质进行了第一性原理研究。利用密度泛函微扰理论，计算了MP2O7晶体的玻恩有效电荷张量、布里渊区中心的红外激活声子频率和介电常数.由于MP_2O_7的复杂结构，其玻恩有效电荷张量也相当复杂。Z * 的值非常大，这意味着MP2O7的共价键性质。带心红外激活模的频率与原子的局域结构和化学环境密切相关。详细分析了其电介质和静态介质的介电常数。理论计算结果表明，MO6八面体对MP2O7的性质起着重要的支撑作用。
A first-principles investigation on the structural and vibrational properties of MP2O7(M = Ti, Zr and Hf) has been performed. Using density functional perturbation theory, the Born effective charge tensors, the IR-active phonon frequencies at the center of the Brillouin zone, and the dielectric constants of MP2O7are obtained. Due to the complex structure of MP2O7, the Born effective charge tensors are quite complex. The anomalously large values ofZ*implies the covalent bonding nature of MP2O7. The frequencies of zone center IR-active modes are closely related to the local structural and chemical environments of atoms. The electronic and static dielectric permittivities are analyzed in detail. The theoretical results highlight the vital role of MO6octahedron underpinning the properties of MP2O7.