Strain tuned magnetic anisotropy in nickel-zinc ferrite thin films

Spinel ferrites are an interesting class of materials with high Curie temperatures, and their magnetic anisotropy is highly sensitive to strain. Here, we report the strain tuning of the magnetic anisotropy in pulsed laser deposited nickel-zinc ferrite thin films. In particular, in-plane strain tuning from compressive (-0.6%) to tensile (+0.5%) results a change in the nature of intrinsic magnetic anisotropy (Ku) from in-plane (-14.3 kJ m-3) to out-of-plane (0.1 kJ m-3). The strain-induced changes in the crystal structure are probed via lattice parameter evolution as well as Raman modes. Magnetic hysteresis indicate presence of hard and soft magnetic phases which are linked with the strain evolution. Further, micromagnetic simulations explain the interplay among hard and soft magnetic phases.