Anharmonic Relaxation Times of Molecular Vibrational Modes in Alkali Halide Crystals

Low-temperature infrared-saturation and hole-burning measurements have been performed on an internal vibrational mode of a spherical-top molecule embedded in a variety of alkali halide crystals. The vibrational relaxation times T1 and T2 satisfy the relation T2≅2T1 but T1 (≤ 38 nsec) is orders of magnitude smaller than expected for multiphonon decay. A study of the alkali halide dependence of these relaxation times suggests that a specific combination of internal, local, and band modes is involved in the decay process. © 1981 The American Physical Society.