James H. Parker

Temperature dependence of the Raman lines of α-Al2O3☆

Abstract The temperature dependence of the frequencies and line-widths of the Raman active lattice modes of α-Al2O3 has been measured between 77° and 1200°K. The temperature dependence of the frequencies is compared with the results of Schauer based on a thermal expansion model and the temperature dependence of the linewidths is compared with the results from a simple two and three phonon decay model.

Raman Scattering by Optical Modes of Metals

Raman scattering by the optical modes of the metals Zn, Mg, and Bi has been observed. The measurements were carried out using argon ion laser excitation. One line was observed for each of the hexagonal close packed metals, Zn and Mg, and two lines were observed for Bi. The frequencies that were obtained are: Zn: 70 cm-1, Mg: 120 cm-1, and Bi: 65 cm-1 and 90 cm-1. These frequencies agree reasonably well with neutron scattering data. The temperature dependence of the Raman linewidths are discussed for the above metals.