Moessbauer Study of Iron Films Produced by Laser Ablation

Iron atoms evaporated by laser ablation were deposited on Al substrates and Si substrates. The iron and alloy (Fe-Al and Fe-Si) films thus formed were evaluated using Moessbauer spectroscopy in order to study their magnetic and chemical properties. Neat iron films (thicker than 50 nm) deposited on Al substrates at 10 K were found to have spin orientations parallel to the surface plane. Formation of Fe-Al alloy was observed at the boundary between the Fe-films and the Al substrate, and the composition of the Fe-Al alloy was a function of the Al substrate temperature during the deposition. Doublet absorption of FeAl was observed for the sample formed at 10 K, and distributed magnetic splitting with disordered compositions of Fe-Al alloy was observed for the samples formed at 293 K. When the sample was formed at 573 K, two sets of sextets with sharp absorptions were observed indicating the formation of Fe3Al. The films were also examined using scanning electron microscopy (SEM). Similarly, samples of laser-evaporated iron on Si substrates were studied, and alloys of Fe-Si were found. Fe3Si and FeSi were produced when the laser-deposition was performed on Si substrates at 573 K