Magnetostriction constants of sputtered FeTaN single crystal thin films

Abstract

FeTaN single crystal thin films were grown to investigate the dependence of the magnetostriction constants, /spl lambda//sub 100/ and /spl lambda//sub 111/ 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)/spl par/(100) and [100]/spl par/[110] with a small fraction of (221)/spl par/(100) due to twinning. The values of |/spl lambda//sub 100/| and |/spl lambda//sub 111/| relative to pure Fe decreased by a factor of /spl sim/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 /spl lambda//sub 100/ and /spl lambda//sub 111/ shows a considerable discrepancy at higher nitrogen content with published experimental data.