An investigation on the mechanical properties of soft magnetostrictive FeCoCr films by nanoindentation

Mechanical properties of soft magnetostrictive FeCo-based thin films is one of the critical properties along with their magnetic properties. To fully exploit their potential in magnetic-microelectromechanical (MagMEMs) application, the elastic and inelastic properties as well as the strength need to be considered. This paper presents the mechanical properties of soft magnetostrictive FeCoCr films at varied Cr concentrations from 2.6 to 9.6 at.% fabricated by RF Sputtering. Nanoindentation was performed to determine the hardness, elastic recovery, Young’s modulus, and the yield strength of the FeCo and FeCoCr films. Although the Cr substitutions slightly reduced the hardness and the Young’s Modulus, the yield strength of the films improved, with a maximum of 1014 MPa for 9.6 at.% Cr. This suggests that the Cr atoms were responsible for inhibiting the dislocations motion in the soft magnetostrictive FeCo-based films and helped to overcome the brittleness of the FeCo.