Voltage controlled magnetic properties and perpendicular magnetic anisotropy of Co₂FeSi alloy thin films

A series of Pt/Co₂FeSi/MgAl₂O₄/Pt thin films with Co₂FeSi thicknesses ranging from 4.5 to 6 nm are constructed to evaluate the influence of applied voltage on magnetic coercivity. It is found that the change in coercivity is around 50.04% at an applied voltage of 16 V for a 5.5 nm thin film, but increases significantly to 72.24% for a 6 nm thin film. We show evolution of perpendicular magnetic anisotropy (PMA) properties of Co₂FeSi amorphous thin films with varying thickness. The polarization of External Hall Effect (EHE) and Magneto-Optic Kerr Effect (MOKE) loops match well with magnetic hysteresis. The EHE coefficient R_s rises from 2.0 × 10^–10 to 5.5 × 10^–10 Ω cm/G with increase in thickness from 4 nm to 6.5 nm, respectively. The voltage controlled the magnetic properties of Co₂FeSi thin films might be beneficial in the development of low-power magnetic tunnel junctions [MTJs].