Formation and Magnetic Properties of Metastable Fe₉₂Bi₈ Nanocrystalline Solid Solution

Abstract

Mechanical alloying was first employed to make supersaturated solution of Fe-Be, which is immiscible under an equilibrium condition at ambient temperature. A nanocrystalline alloy was successfully produced by mechanical alloying for the composition of Fe92Bi8that could hardly be formed by the rapid solidification of melted alloys. The changes of structure and magnetic properties of milled Fe92Bi8with the milling time were studied by using XRD, DSC and saturation magnetization (σs) measurements. The nanocrystalline solution is of bcc structure of α-Fe after 160h milling and the crystal size reaches 8nm after 200h milling. The σsof Fe92Bi8decreases with the increasing of the milling time. After 200h milling, the σsdecreases to a value of 156Am2/kg.