OPTICAL-ABSORPTION OF U-CENTER IN MIXED ALKALI-HALIDE CRYSTALS

The shift with concentration variation on the optical-absorption of U band in KCl:KBr and KC:NaCl mixed crystals was studied by use of point-ion and size-ion correction models. We found that using the Bartram et al. method there is not appreciable correction to the point-ion energies. Assuming, for the ground state, that the electrons are concentrated at the lattice site, the calculated energies are in good agreement with the experimental results for KC1, KBr and NaCl in pure state. © 1990, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.