Microstructure and magnetic properties of binary Nd80Fe20 with Ga additions

In this work, structural and magnetic properties of metastable Nd-rich Nd80Fe20 binary and (Nd-Ga)80Fe20 ternary alloys are investigated. The specimens were prepared at different cooling rates, varying from 5 to 150 K/s by using copper mold casting and at 106 K/s by melt spinning. Specimens with different dimensions were prepared in order to change the cooling rate. The aim of the present work was to characterize a metastable hard magnetic phase referred to as 'A1' in Nd80Fe20 alloys, which forms as a part of the fine eutectic depending on the cooling rate. In order to stabilize the formation of A1, (Nd100-xGax)80Fe20 (x = 5, 10, 15) alloys were rapidly cooled at a solidification rate of ? 150 K/s.