Soft magnetic properties and glass formability of Y–Fe–B–M bulk metals (M = Al, Hf, Nb, Ta, and Ti)

Abstract

The glass formability, magnetic properties and thermal stability of the Y–Fe–B–M bulk metals (M = Al, Hf, Nb, Ta, and Ti) alloys have been investigated. For (Y 0.06Fe 0.72B 0.22) 98M 2 series alloys, Al or Hf addition deteriorates the glass forming ability (GFA), but Nb or Ta addition broadens supercooled region from 50.2 °C for ternary rod to 61.5 °C for M = Ta and 62 °C for M = Nb, respectively. The bulk glassy rod as large as 3 mm in diameter can be obtained. However, their magnetization and Curie temperature are reduced due to the magnetic dilution by the addition of these nonmagnetic elements. On the other hand, for Y 4Fe 72B 22M 2 series alloys, almost all the substitution elements, except Al, can improve GFA of alloy rod, making the diameter of bulk glassy rod as large as 3 mm for Ti or Hf substitution and 4 mm for Ta or Nb substitution, respectively. It is arisen from the further expansion of the supercooled region to 70.4–84.2 °C. In this study, Y 4Fe 72B 22Ta 2 amorphous rod displays the optimal glass forming ability and also good soft magnetic properties of σ s = 123 emu/g, H c = 0.2 Oe, and T C = 276 °C.