In-plane anisotropy and magnetostriction constants ofFe/Ga0.8In0.2As films with Cr overlayers

Abstract

Thin Fe films on the lattice-matchedGa0.8In0.2As substrate were investigated as part of a determination of the origin of the in-plane uniaxialanisotropy that is present in Fe/GaAs and Fe/InAs films. The epitaxial Fe films were grownusing molecular beam epitaxy (MBE), and were capped with a Cr overlayer. The in-planeanisotropies of each film were inferred from the normalized magnetization loopsmeasured using a magneto-optic Kerr effect (MOKE) magnetometer. Using a fittingmethod to the magnetization data, the cubic and uniaxial anisotropy constantsfor each film were determined. The Villari method was used to determine themagnetostriction constants. For all the films, they were negative, and becamemore negative as the Fe thickness decreased. The magnetic parameters of theFe/Ga0.8In0.2As films were compared with those of the Fe/GaAs and Fe/InAs films, to determine the originof the uniaxial in-plane anisotropy.