Magnetostriction constants of sputtered FeTaN single crystal thin films

FeTaN single crystal thin films were grown to investigate the dependence of the magnetostriction constants, λ₁₀₀ and λ₁₁₁ on nitrogen content. Films with 5 wt.% Ta and different nitrogen contents were prepared by dc sputtering on MgO (100) substrates at elevated temperatures. The films´ principal orientation with respect to the substrate were (100)||(100) and [100]||[110] with a small fraction of (221)||(100) due to twinning. The values of |λ₁₀₀| and |λ₁₁₁| relative to pure Fe decreased by a factor of ~2 to a minimum near 2 at% nitrogen and then slowly increased at higher nitrogen content. The saturation magnetostriction calculated for a polycrystalline material using the measured values of λ₁₀₀ and λ₁₁₁ shows a considerable discrepancy at higher nitrogen content with published experimental data