Moessbauer study of structural relaxation in amorphous YFe2

This paper reports the microscopic aspect of the structural relaxation observed by the electric quadrupole effect in the Moessbauer effect and a discussion on a relation of the uniaxial magnetic anisotropy of amorphous GdCo with the microscopic mechanism of the structural relaxation. The samples were amorphous films deposited on aluminum substrates by r.f. sputtering method. The target was an arc-melted alloy of YFe2. The sputtering rate of the sample A was about 2 μm/hour, and that of the sample B was less than 1 μm/hour. The sample B had a non-uniform distribution of constituent atoms. The Moessbauer spectra of Fe-57 in the samples A and B were obtained. The spectrum is a quadrupole doublet. The isomer shift and the quadrupole splitting for both samples were equal within experimental error. The obtained spectra showed a reflection of the difference in the microscopic structure of the alloys. The structural relaxation of amorphous alloys produces the change in the topological atomic short-range order and the compositional atomic short-range order. A large change in the CSRO was observed in the alloy with a non-uniform atomic distribution. (Kato, T.)