LONG-WAVELENGTH PHONONS IN GATE

The long-wavelength vibrational modes of monoclinic GaTe have been investigated by Raman scattering and far-infrared absorption and reflection. The energies of 14 of the expected 18 Raman-active modes have been measured and their symmetries identified. Ten of the 15 predicted infrared-active modes have been found in the infrared spectra. A comparison of the Raman and infrared results has not provided conclusive evidence concerning the existence of conjugate modes in GaTe, and possible reasons are discussed. The results are also compared to previous work and several differences are noted and discussed in detail. © 1979 The American Physical Society.