Magnetic anisotropy changes in ultrathin Co films grown on vicinal sapphire substrates

Abstract

The aim of the work is to study the magnetic anisotropy changes in epitaxial ultrathin Co films grown on vicinal sapphire substrates with different miscut angles. Changes of the in-plane magnetic anisotropy symmetry were deduced from magnetooptical hysteresis loops shape and angular dependence analysis of the resonance field measured in the sample plane. Two-fold and four-fold symmetry of the in-plane anisotropy was observed for different miscut angles. The experimental data are discussed taking into account the following energy contributions: (i) demagnetization; (ii) perpendicular uniaxial anisotropy (iii) and step-induced uniaxial anisotropy. Magnetic anisotropy constants are fitted to the experimental results for different miscut angles.