Asymmetric magneto-optic response in epitaxial Fe(110)/Mo(110) thin films

We have observed asymmetric hysteresis loops that are inherent in the magneto-optic response of an epitaxial Fe(110)/Mo(110) thin film. We trace the origin of the asymmetry to a second order term in the magneto-optic response that is proportional to the transverse times of the longitudinal component of the magnetization. We determine the first order term of the magneto-optic response experimentally and fit the second order term to the data.