Strain engineering for controlled growth of thin-film FeNi L10

Abstract

FeNi thin films in the L10 phase were successfully grown by magnetron sputtering on HF-etched Si substrates on Cu/Cu100−xNix buffers. The strain of the FeNi layer, , was varied in a controlled manner by changing the Ni content of the Cu100−xNix buffer layer from to , which influenced the common in-plane lattice parameter of the CuNi and FeNi layers. The presence of the L10 phase was confirmed by resonant x-ray diffraction measurements at various positions in reciprocal space. The uniaxial magnetocrystalline anisotropy energy is observed to be smaller (around 0.35 MJ m−3) than predicted for a perfect FeNi L10 sample, but it is larger than for previously studied films. No notable variation in with strain state is observed in the range achieved (), which is in agreement with theoretical predictions.