KTa_(0.5)Nb_(0.5)O_3电子结构的第一性原理研究

First Principles Study on Electronic Structure of KTa_(0.5)Nb_(0.5)O_3

用全电势线性缀加平面波法 (FLAPW )计算了KTa0 .5Nb0 .5O3 铁电相和顺电相的态密度、能带结构 .通过对两相态密度的对比分析我们发现在铁电相 ,钽原子的d电子和氧原子的 2p电子以及铌原子d电子与氧原子的 2p电子之间存在强烈的轨道杂化 ,对能带的分析也得出同样的结论 .这种轨道杂化对KTa0 .5Nb0 .5O3 铁电性的稳定有着重要的意义 .钽原子在四方铁电体KTa1 xNbxO3 中的作用与在纯钽酸钾中的作用有明显的差别 .

The full potential linearized augmented plane wave method within the generalized gradient approximation was used to calculate electronic structure of ferroelectric and paraelectric KTa0.5Nb0.5O3. We calculated the density of states and band structure. From the density of states analysis, it is shown that the hylinidization between B(Ta, Nb) d and O p is very important to the ferroelectric stability of KTa0.5Nb0.5O3. This is consistent with the analysis of band structure.