Optical properties of the group-IV<i>B</i>refractory metal compounds

Abstract

We have calculated ab initio the direct interband electric dipole transitions of the carbides, nitrides, and oxides of Ti, Zr, and Hf in the rocksalt structure using the full-potential linear muffin-tin orbital method. The dipole matrix elements are calculated explicitly. Our results are in extraordinarily good agreement with experiment. The optical spectra are analyzed and we explain the origin of the different structures in the spectra in terms of the calculated electronic structure. We also discuss the trends in the optical properties as the metal and nonmetal atom types are changed and how these trends relate to general concepts such as band filling, nuclear charge, and bandwidth. \textcopyright{} 1996 The American Physical Society.