顺电相PbTiO3晶体的电子结构和光学性质

应用全电势线形平面波缀加方法对铁电晶体钛酸铅的顺电立方相的电子能带结构、态密度、电子密度分布进行了计算.能带结构的计算结果表明立方顺电相晶体PbTiO₃为直接带隙的半导体,带隙大小为1.7eV.通过态密度和电子密度的计算结果分析,得到价带和导带的电子组成情况,并且指出Ti原子和O原子存在较强的共价键合.在电子结构的计算基础上,计算得到了与实验符合较好的PbTiO₃晶体的介电函数的实部和虚部,分析了虚部所对应的能带跃迁,并得到了其它的光学性质的参数(光学吸收系数、折射率、消光系数、能量损失曲线、反射率).

Electronic and optical properties of PbTiO3 cubic phase

Using FP-LAPW (full potential linear augment plane wave) method, the electronic band structure, DOS (density of states), and charge density contours of ferroelectric PbTiO₃ bulk in cubic paraelectric phase were calculated with GGA (generalized gradient approximation) exchange correlation. Band structure calculations show that a directed band gap of 1.7eV at Χ point in the first Brillouin zone. The results from analyzing the DOS and charge density contours show that the bonding between Ti and O atom is covalent. The optical properties of PbTiO₃ were also discussed according to the result of the electronic structure. The dielectric function, reflectivity, refractive index, extinction coefficient, absorption coefficient, and the energy loss spectrum were presented