Relaxation and IR Spectroscopic Properties of the CN(-)Stretching Mode in SilverHalides

摘要

The relaxation times of the CN(-) stretching mode in AgCl and AgBr at 1.7 K arefound to be a few hundred microseconds. These times are shorter by more than two orders of magnitude than those for CN(-) in most alkali halides. High frequency local modes discovered in the silver halides are suggested to act as fast relaxation channels causing this difference. Reexamination of CN(-) doped sodium halides also reveals a local mode clearing up the previously found short times in these materials, too. An energy gap law fits all data.