Temperature dependence of permeability for Fe–Cu–M–Si–B alloys

The correlation between initial permeability and temperature (μi–T curve) for Fe–Cu–Nb–Si–B, Fe–Cu–Nb–V–Si–B and Fe–Cu–Mo–Si–B alloys annealed at 300–610°C was investigated. Three types of μi–T curve were observed. The corresponding phase structure of alloy for the three types of μi–T curve was analyzed and the magnetic coupling between nanocrystalline grains versus μi–T curve as well as the reasons for the changes of μi–T with temperature were also discussed.