Raman Scattering and Phase Transitions of V_2O_3 (Physics)

Raman scattering in single crystals of V_2O_3 has been studied in the range from ～20K to room temperature Metal to insulator crystallographic, and anti-ferromagnetic-ordering transitions take place concurrently at T_1～150K. The observed spectra showed a drastic change at T_1. On either side of T_1, peaks were observed which had intensities rather insensitive to the variation of temperature. These peaks are identifiable as phonon excitations, and the peaks of the two temperature regions can be correlated on the basis of the structural transition of the crystal. One peak was observed in the low-temperature region, the intensity of which decreased strongly with increasing temperature, becoming unobservable at T[≳]T_1. Clearly, this peak involved the excitation of magnons which resulted from the magnetic transition