MOSSBAUER STUDY OF MAGNETIC-INTERACTIONS IN NANOCRYSTALLINE FE73.5CU1NB3SI16.5B6

Mossbauer spectroscopy has been used to follow the temperature-depende nt magnetization in the temperature range 4.2-823 K of the amorphous a s well as the nanocrystalline grains in partially crystallized Fe73.5C u1Nb3Si16.5B6 alloy. In nanocrystallized specimens, the magnetization behaviour of both amorphous and nanocrystalline components is signific antly different from that of the bulk amorphous or crystalline Fe3Si. Initially the nanocrystalline grains exhibit a superparamagnetic behav iour above the Curie temperature of the amorphous matrix. With increas ing density of nanocrystalline grains, the superferromagnetic interact ion between the grains becomes important.