Magnetization, anomalous barkhausen effect, and core loss of supermendur under high temperature cycling

The magnetization and core loss of Supermendur were measured up to 900°C under conditions of slow temperature cycling in vacuum. As a consequence of this heating the coercivity at 25°C increased from 21 A/m to about 110 A/m. This increase is less than previously reported. A prominent anomalous Barkhausen effect, pinched-in hysteresis loops, and a magnetic viscosity field in excess of 20 A/m were observed in the range 600 to 700°C. At 850°C Super-mendur had a coercivity of 23 A/m, a saturation induction exceeding 1.5 T, a core loss of 26 W/kg at 400 Hz, and of 1.5 T. Super-mendur may be useful for high temperature soft magnetic material applications where some history dependence of properties and instability of minor loops at lower temperatures is acceptable.