Local Structure Analysis of SmFe₂ and TbFe₂

Abstract

We performed local structure analysis of SmFe₂ and TbFe₂ in the crystallization process from amorphous by using synchrotron X-ray pair-distribution function (PDF) method. The giant mangetostrictive materials of these compounds can be controlled its property by ion irradiation. In amorphous TbFe₂ and SmFe₂, the mosaic block size was small and the short-range order structure owing to Fe-Fe network maintained. In crystalline SmFe₂, a rigid long-range order structure of Fe-Fe and Sm-Sm network coexisted and it had a large mosaic block size. On the other hand, in crystalline TbFe₂, Fe-Fe network degraded by Tb-Tb network owing to its lattice tolerance. The difference of the local structure is a cause of the difference in the Ar-ion irradiation effect.