Effect of Low Substrate Temperature on the Magnetic Properties and Domain Structure of Fe70Ga30 Thin Films

We report on the effect of low substrate temperature on the correlation between structure, magnetic properties, and micromagnetic behavior of Fe70Ga30 thin films. The enhanced grain size and the decrease in the number of pinning centers are in correlation with the enhanced saturation magnetization and domain size (similar to 0.2-0.5 mu m), respectively. Estimated effective magnetic anisotropy energy (K-eff) is found to increase with substrate temperature from 7.5 x 10(5) J/m(3) (room temperature) to 13.6 x 10(5) J/m(3) (350 degrees C). The coercivity variation from the object-oriented micromagnetic framework (OOMMF) simulation is in line with respect to experimental values. Spin structure from simulation also indicates multiple-domain configuration when there is a magnetization reversal.