Magnetic and magneto-optical properties of epitaxial cobalt films grown on a corrugated CaF2/Si surface

Abstract

The magnetic properties of CaF2/Co/CaF2(110)/Si(001) heterostructures fabricated by molecular-beam epitaxy and having a corrugated CaF2 buffer surface were studied. The optical and magneto-optical properties of these structures reflect the C2v symmetry of the corrugated structure surface. The studies of hysteresis loops using the longitudinal and transverse magneto-optical Kerr effects under oblique light incidence and of magneto-optical phenomena under near-normal light incidence demonstrate that the corrugated structure surface leads to optical and magneto-optical anisotropies. The magnetization of such structures occurs via coherent magnetization rotation over a wide magnetic-field range. The magnetic anisotropy of these structures is described using a Gaussian distribution of easy axes of magnetization in cobalt granules about the direction parallel to the groove direction. The asymmetry of hysteresis loops of the rotation of the plane of polarization detected under oblique and normal light incidence is shown to be related to the contributions to the effective film permittivity that are quadratic in the magnetic moment.