Magnetostrictive properties of Co-Fe alloy epitaxial thin films with Co-rich composition

Co75Fe25 (at. %) alloy films of 100 nm thickness are prepared on MgO(001) and (110) single-crystal substrates. A Co75Fe25(001)(bcc) single-crystal film is epitaxially grown on the MgO(001) substrate, whereas a Co75Fe25(211)(bcc) bi-crystalline film is formed on the MgO(110) substrate. The out-of-plane and in-plane lattice spacings of Co75Fe25 films are in agreement with the bulk values within small differences of less than 1%. The out-of-plane and in-plane orientation dispersions are smaller than 2(degrees). These results show that well-defined Co75Fe25 epitaxial films consisting of single bcc phase are successfully obtained on both the MgO(001) and (110) substrates. The in-plane magnetic anisotropies of single- and bi-crystalline films are confirmed to be reflecting the magnetocrystalline anisotropy of Co75Fe25 crystal with the easy < 111 > and < 100 > hard axes and the demagnetization field. The magnetostriction coefficients, (lambda(100), lambda(111)), of single- and bi-crystalline films are determined to be (+60x10(-6), +150x10(-6)) and (+55x10(-6), +185x10(-6)), respectively. The present study has shown that a Co-Fe alloy with Co-rich composition has positive moderately-large lambda(100) and fairly-large lambda(111) values. (C) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).