Structural and Magnetic Properties of Co₂FeAl_0.5Si_0.5 Full-Heusler Alloy Thin Films on GaAs Substrates

Abstract

We investigated the structural and magnetic properties of Co₂FeAl_0.5Si_0.5 (CFAS) thin films on GaAs substrates. The CFAS thin films grew epitaxially on GaAs with CFAS (100)[100] || GaAs (100)[100] relation and formed an ordered L2₁ structure with substrate heating deposition at T_SUB=300°C, 400°C and post annealed at T_PA=400°C. Moreover, we confirmed the no reaction between CFAS and GaAs. The CFAS thin films on GaAs showed strong uniaxial magnetic anisotropy with an easy axis of [110]_CFAS ([110]_GaAs) direction and the magnetic anisotropy generally increased by decreasing the thickness of CFAS. The magnetic moment of the CFAS film deposited with substrate heating at 300 °C was approximately 4.8 μ_B/f.u. at room temperature.