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

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-B2Fe7.6Zr0.4]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-B2Fe7.6Zr0.4]Fe (Fe71.7B16.7Si8.3Zr3.3). Our experimental results show that the critical glass formation size gradually decreases from 2.5 mm to 1 mm with increasing Fe-content. Si-B2Fe7.6Zr0.4]Fe + Fe-2.5 (Fe76.5B13.8Si6.9Zr2.8) glassy alloys exhibit high saturation magnetization of B-s similar to 1.54T and a very low coercive force of H-c similar to 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. (C) 2016 Published by Elsevier B.V.