THE NI-GAMMA-FE INTERFACE - HYPERFINE MAGNETIC-FIELD AND MAGNETIC-ANISOTROPY

Conversion Electrons Mossbauer Spectroscopy (CEMS) is used to study the magnetic polarization state and the magnetic anisotropy of ultrathin Fe/Ni films in multilayer samples with two, one and any Fe/Ni interface. The analysis of the distribution function of the hyperfine fields indicates a magnitude of 34 T for the Fe/Ni interface field and gives evidence of the existence of a pure, highly susceptible gamma-Fe phase. Results corresponding to intermixed regions suggest enhanced hyperfine fields and magnetic moments in local environments with more than 6 and up to 9 nearest Fe neighbor atoms, and low fields in Fe sites with 10-11 Fe neighbors. Out-of-plane perpendicular anisotropy is found only in samples having an Fe/Ni interface.