Magnetostrictive properties of sputter-prepared Fe71Co10Ga19 films on Si (100) substrates

Magnetostrictive and structural properties of sputter-prepared Fe71Co10Ga19 films on Si(100) substrates have been studied. The experimental results show that the saturation magnetostriction (lambda s) of the films is mainly dominated by the amount of m-D0(3) phase existed in the films through the modification of the sputtering parameters, including Ar gas pressure (P-Ar) and sputtering power (P). Large lambda s of 113.7 ppm is attained for the 20 0-nm-thick Fe71Co10Ga19 film made under the conditions of P-Ar = 30 mTorr and P = 40 W. Besides, the thickness (t) dependence of lambda s in the Fe71Co10Ga19 films is that: (a) in the region of 200 nm >_ t >_ 50 nm, lambda s increases from 113.7 to 164.7 ppm as t decreases; (b) in the region of 50 nm >_ t >_ 30 nm, lambda s decreases to 128.1 ppm as t continues to decrease. The increase of lambda s in the region (a) may be related to surface contribution involved by surface roughness. The decrease of lambda s in the region (b) results from the surface oxidation of film. The optimized lambda s of 113.7-164.7 ppm achieved for Fe71Co10Ga19 film in this study is superior to those (49-80 ppm) of the previously reported Fe81Ga19 thin films. The results of this work provide useful film-making information to obtain the Fe71Co10Ga19 film with outstanding structure and magnetostrictive properties for applications. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The saturation magnetostriction of sputter-prepared Fe71Co10Ga19 films on Si(100) substrates is mainly influenced by the amount of m-D0(3) phase and can be controlled by adjusting sputtering parameters. The thickness dependence of magnetostriction shows an increase in lambda s as thickness decreases in the range of 200 nm to 50 nm, while a decrease is observed in the range of 50 nm to 30 nm.