Intermixing during epitaxial growth and Mössbauer spectroscopy with probe layers

Abstract

Mossbauer spectroscopy with 57Fe (119Sn) probe layers is a useful method to study the local magnetic structures at buried interfaces. However interface alloying, which always exists in the real samples, have to be taken into account for accurate interpretation of experimental data. We developed an algorithm, which describes the interface intermixing in the multilayers. Substituting deposited atoms by atoms of substrate and floating of deposited atoms in the upper layers during epitaxial growth leads to the formation of asymmetric chemical and magnetic interfaces. This asymmetry in the M1/M2 superlattices can explain the difference between magnetic responses from M1 on M2 and M2 on M1 interfaces which were observed in experiments. Applying this intermixing model to the systems with probe layers located at different distances from the interfaces gives the natural explanation of hyperfine fields distributions on probe atoms and helps us clarify some discrepancies reported in the literature.