The Effect of Temperature and Film Thickness on Domain Wall Energy Density, Coercivity Force, and Magnetostriction of Galfenol Films

Galfenol thin film exhibits a promising future for applications in MEMS, switches, and sensing because of its notable magnetostriction property and favorable soft dynamic behavior. Here, we report an investigation into the alterations in surface islands and magnetic domain structure of galfenol thin film using atomic force microscopy (AFM) and magnetic force microscopy (MFM) following a heating and cooling process. A MATLAB-based stereological method was employed to calculate the domain width (
$D_{w}$
) and domain wall energy density (
$\gamma _{w}$
) of galfenol thin film. We found an increase in domain width and a decrease in domain wall energy density, as well as variations in the effectiveness of magnetostriction (
$\lambda _{s}$
) and coercivity force (
$H_{c}$
) with increasing temperature. The influence of film thickness on magnetostriction and coercivity force were investigated as well.