Magnetic and structural properties of Co2FeAl thin films grown on Si substrate

The correlation between magnetic and structural properties of Co2FeAl (CFA) thin films of different thicknesses (10 nm < d < 100 nm) grown at room temperature on MgO-buffered Si/SiO2 substrates and annealed at 600 degrees C has been studied, x-ray diffraction (XRD) measurements revealed an (011) out textured growth of the films. The deduced lattice parameter increases with the film thickness. Moreover, pole figures showed no in plane preferential growth orientation. The magneto optical Kerr effect hysteresis loops showed the presence of a weak in plane uniaxial anisotropy with a random easy axis direction. The coercive field, measured with the applied field along the easy axis direction, and the uniaxial anisotropy field increase linearly with the inverse of the CFA thickness. The microstrip line ferromagnetic resonance measurements for in plane and perpendicular applied magnetic fields revealed that the effective magnetization and the uniaxial in plane anisotropy field follow a linear variation versus the inverse CFA thickness. This allows deriving a perpendicular surface anisotropy coefficient of -1.86 erg/cm(2). (C) 2014 Elsevier B.V. All rights reserved.