Internal stress influence on the coercivity of FeCuNbSiB thin films

The effects of thickness on magnetic properties of FeCuNbSiB sputtered thin films

“…This can be ascribed to a variety of causes and, mainly, to the internal stresses. Magnetic softness is highly dependent on the internal stress in magnetostrictive materials [4,5]. These results suggest that internal stresses increase the coercivity as the thicknesses decrease; these results are in agreement with those reported by some other studies [5][6][7].…”

“…Possible sources for the internal stresses are deposition technique and mismatch between the lm and substrate. The sputtering technique is known for inducing high stress in the deposited lms, which is inversely proportional to lm thickness [5]. It is known that the presence of residual stress a ects the overall indentation response of material and, hence, the measured hardness and modulus.…”

“…The combined e ect of residual stresses and positive magnetostriction in alloy force the magnetic moments to align toward the stress-induced anisotropy direction. For the thinnest lm, the pinning of the domain walls at the surface irregularities might be an excessive reason [5,10]. Increasing the lm thickness, the contribution of internal stresses, and surface pinning will become less e ective [5,6].…”

“…Among the soft magnetic materials, FeCuNbBSi or so-called Finemet-type alloys are good candidates for such applications due to their excellent magnetic softness. Microstructure and magnetic properties of FeCuNbBSi thin lms have been the subject of di erent studies [5][6][7][8][9][10][11][12][13]. Results have shown that amorphous thin lms exhibit di erent behaviour as compared to the rapidly quenched ribbons.…”

“…Results have shown that amorphous thin lms exhibit di erent behaviour as compared to the rapidly quenched ribbons. Magnetic properties of thin lms can be in uenced signi cantly by internal stresses generated during deposition as well as by surface irregularities [5][6][7]. Internal stresses coupled with a non-zero magnetostriction of the amorphous lms may result in a high magnetic anisotropy.…”