Measurements of Raman intensities and pressure dependence of phonon frequencies in sapphire

Absolute Raman cross sections and mode Gruneisen parameters of the Raman-active optical vibrational modes of sapphire (a = Al2O3) were measured. Intensity measurements show that magnitudes of the Raman tensor components agree very well with group theoretical expectations. Pressure dependence of the frequencies has been measured over a range from 1 to 10 kbars and mode Gruneisen parameters have been calculated.