Magnetic properties and a structure model for high Fecontent Fe–B–Si–Zr bulk glassy alloys

Abstract The present study is devoted to developing high Fe-content Fe-B-Si-Zr bulk metallic glasses (BMGs) with good soft magnetic properties and exploring their structure-property correlations. Using the atomic-cluster-plus-glue-atom model, a series of high Fe-content Fe-B-Si-Zr quaternary alloys, namely [Si-B 2 Fe 7.6 Zr 0.4 ]Fe + Fe x (x = 0, 0.5, 1, 1.5, 2, 2.5 and 3), have been derived from a basic BMG composition formula of [Si-B 2 Fe 7.6 Zr 0.4 ]Fe (Fe 71.7 B 16.7 Si 8.3 Zr 3.3 ). Our experimental results show that the critical glass formation size gradually decreases from 2.5 mm to 1 mm with increasing Fe-content. [Si–B 2 Fe 7.6 Zr 0.4 ]Fe + Fe 2.5 (Fe 76.5 B 13.8 Si 6.9 Zr 2.8 ) glassy alloys exhibit high saturation magnetization of B s  ~ 1.54 T and a very low coercive force of H c  ~ 0.5 A/m. The deceasing tendencies of the glass transition temperature, thermal stability, glass-forming ability and Curie temperature with increasing Fe-content in the series of alloys are discussed in view of the occurrence of micro-segregation of Fe clusters in the model structure.