YbB_6的能带结构和光电导率谱的解析

Band Structure of YbB_6 and Analysis of Its Optical Conductivity Spectrum

用密度泛函(GGA+U)方法研究YbB6晶体的电子结构。采用FLAPW方法进行计算,获得了比较精确的能带结构信息。分析了YbB6能带结构的特征与Yb-B6簇间成键情况的联系。在此基础上计算YbB6的反射率、介电函数、光电导率和能量损失函数等光学常数,结果与实验值符合比较好。对其光电导率(实部)和能量损失函数谱进行详细分析,对谱峰作出指认,阐明了各谱峰与能带间电子跃迁的联系,证实了前人对谱峰所作经验指认的合理部分,补充和纠正了前人经验指认的不足和不准确之处。

The band structure of YbB6 crystal was studied by means of density functional（GGA＋U） method.The calculation was carried out by FLAPW method and the band structure information was obtained with high accuracy.The correlation between the characteristics of band structure and the Yb-B6 bonding in YbB6 was analyzed.On this basis,some optical constants such as reflectivity,dielectric function,optical conductivity and energy-loss function were calculated.The results are in good agreement with the experiments.Analysis of the optical conductivity（real part） and energy-loss function spectra was carried out in detail, and assignment of the spectra was performed to correlate the spectral peaks with the electronic interband transitions,confirming the valid part of the empirical assignment by other authors and supplying some missed assignments as well as correcting the incorrect ones.