Structural and Magnetic Ordering in Fe-Ga Thin Films Examined by Mössbauer Spectrometry

The detailed analysis of atomic and magnetic structure has been performed by Mössbauer spectroscopy for polycrystalline $Fe_{80}Ga_{20}$ films of different thickness ranging from 20 nm to 200 nm. The films were deposited on Si(100) substrate using dual sputtering and evaporation method. Obtained CEMS spectra have been fitted with several Gaussian distributions of hyperfine magnetic field. The results point to the domination of BCC disordered A2 phase and the absence of $DO_{3}$ and $L1_{2}$ phases in the films. Both hyperfine parameters and lattice constant reveal anomaly for 40 nm thick sample - presumably due to the change of the internal stress. Spin texture evolves from in-plane to out-of-the-plane configuration with increasing thickness.