Bulk glassy Fe-Ga-P-C-B-Si alloys with high glass-forming ability, high saturation magnetization and good soft magnetic properties

Abstract

The effect of Si addition on the glass-forming ability and magnetic properties for the Fe77Ga3P12-xC4B4Six and Fe78Ga2P12-xC4B4Six glassy alloys was investigated. For the both alloys, the addition of 2.5 at%Si was found to be effective for the extension of the supercooled liquid region (ΔTx) defined by the difference between the glass transition (Tg) and crystallization temperature (Tx). The ΔTx value is 28 K for the Fe77Ga3P12C4B4 alloy and increases to 48 K for the Fe77Ga3P9.5C4B4Si2.5 alloy. The effectiveness of Si addition can be interpreted in the framework of the three component roles for the formation of bulk glassy alloys and the stabilization of supercooled liquid. The three component rules are satisfied at a high degree of level by the addition of Si. The glassy single phase was obtained in the diameter range up to 2.5 mm for the Fe77Ga3P9.5C4B4Si2.5 glassy alloy and 2.0 mm for the Fe78Ga2P9.5C4B4Si2.5 glassy alloy. The glassy alloys exhibited high saturation magnetization (Is) and good soft magnetic properties, i.e., high Is of 1.36 and 1.40 T, and low coercive force (Hc) of 4.25 and 3.35 A/m, respectively. The high Is and low Hc as well as high glass-forming ability of the Fe-based bulk glassy alloys are promising as a new type of soft magnetic bulk alloy.