The effects of linear and quadratic magneto-optical coupling in the one-magnon Raman spectrum of FeF2

One-magnon light scattering measurements have been performed to investigate the asymmetry of the Raman scattering tensor of FeF 2 at laser wavelengths of 488.0 nm and 514.5 nm. A polarisation analysis was employed, and the results were interpreted theoretically in terms of linear and quadratic magneto-optical coupling. The importance of quadratic magneto-optical coupling was confirmed at these wavelengths, and the data enabled the ratio of quadratic to linear magneto-optical coefficients to be uniquely determined at each wavelength. Further support for these results and the theoretical analysis was provided by measurements of the 'anomalous' ratio of intensities for anti-Stokes and Stokes scattering.