Abstract
The polarization-dependent absorption spectra and wavelength-modulated absorption spectra of Ti have been measured under very-high-resolution conditions between 1.6 and 300°K. For the first time the fine structure of the fundan ental absorption edge is resolved and a detailed investigation is presented. We find an indirect allowed transition , characterized by a small doublet (3.061-3.065 eV at 1.6°K) which constitutes the fundamental transition in polarization parallel to . In polarization perpendicular to , we find the same indirect transition plus a new forbidden direct transition which appears at slightly lower energy (3.031 eV at 1.6°K). The fine structure of the forbidden exciton is resolved and the ionization energy is 4 meV.
- Received 21 June 1977
DOI:https://doi.org/10.1103/PhysRevB.18.5606
©1978 American Physical Society