Magnetic Domain Structure of Galfenol at Elevated Temperatures

Galfenol (iron–gallium) has a great potential in MEMS applications owing to its high magnetostriction constant, low saturation field, and resilience to bending, compressive, and tensile loading. Here, we report on the expansion/shift of the topography and the expansion/shift of the magnetic domain structure of galfenol observed at high temperatures via atomic force microscopy (AFM) and magnetic force microscopy (MFM). The maze-like domain pattern and stripe-like domain pattern are observed in the perpendicular and parallel surfaces. The spike and reverse domains are observed in 3-D view via XEI imaging software. A MATLAB-based stereological method was used to obtain the domain width and domain wall energy density. An increase in domain width and decrease in domain wall energy density was identified when temperature increased from room temperature to 150 °C.