Effect of annealing temperature on magnetic aftereffect and positron lifetime in Fe73.5Cu1Nb3Si13.5B9 alloy

The magnetic aftereffect and the positron lifetime were measured at room temperature in the Fe73.5Cu1Nb3Si13.5B9 alloy under as-quenched condition and under the conditions annealed at a range of temperatures ta from 450 °C to 750 °C respectively. It was found that both the magnetic after-effect and the positron lifetime decrease monotonically with increasing ta if ta&le600 °C. When ta≥650 °C, magnetic aftereffect is essentially suppressed and two positron lifetimes appear. The results show that the magnetic aftereffect is mainly contributed by the amorphous phase in the materials because there are a lot free volume in the amorphous phase.