LIGHT-SCATTERING BY SPIN EXCITATIONS IN COPPER-OXIDE-BASED MATERIALS

In this paper we present a study of spin dynamics in CuO, Bi2CuO4 and CuGeO3 single crystals using Raman spectroscopy. The measurements of p olarized Raman scattering spectra are performed in the temperature reg ion from 10 to 300 K in various frequency ranges. We found and assigne d the lines in the spectra that belong to magnetically ordered phases. The origin of these excitations, based on the temperature dependence of their energies, linewidths and symmetry arguments, is given. Also, we present calculations of two-magnon intensities, based on the densit ies of states, and compare them with experimental data. (C) 1998 Acade mic Press Limited.