STRUCTURE AND MAGNETIC-PROPERTIES OF FE100-XSNX(3.2-LESS-THAN-X-LESS-THAN-62) ALLOYS OBTAINED BY MECHANICAL MILLING

The structure and magnetic properties of mechanically ground Fe-Sn all oys have been studied by X-ray diffraction, magnetic measurements, and Fe-57 and Sn-119 Mossbauer spectroscopy. It has been shown that the a lloys are nanocrystalline and have the disordered bcc structure with S n concentrations x < 32.7 at%, and disordered hexagonal-like structure s with x > 32.7. The concentration dependences of the magnetic orderin g temperature, average magnetic moment per Fe atom, average hyperfine magnetic field and isomer shift, as well as those of the bcc lattice p arameter and grain size are nonlinear and reveal a number of peculiari ties at 12-15, 25 and 50 at% Sn. The ferromagnetic state is shown to f orm in alloys with x < 50, the concentration range of cooperative magn etism existence being 0-72 at% Sn. We have compared the magnetic prope rties of nanocrystalline Fe-Sn alloys with those of similar Fe-Si allo ys and amorphous Fe-Sn films. We describe the essential differences be tween the Fe-Sn and Fe-Si systems, and assess the influence of the abs ence of topological disorder on the magnetic properties of non-ordered Fe-Sn alloys on the other.