Microstructure and Soft Magnetic Properties of Nanocrystalline Fe_74.5Cu₁Nb₂Si_17.5-xGa_xB₅ Alloys (x = 1, 2, 3)

The effects on the microstructure and soft magnetic properties of Fe_74.5Cu₁Nb₂Si_17.5-xGa_xB₅ alloys (x = 1, 2, 3) using Ga to partially replace Si are investigated. It is found that the Ga substitution in Fe_74.5Cu₁Nb₂Si_17.5B₅ alloy reduces the onset primary crystallization temperature (T_X1) and enlarges the interval temperature (ΔT_X), which correlates with the precipitation of soft magnetic crystalline phase. Substituted 3at% Si by Ga, the initial permeability of nanocrystalline alloy possesses a large value of 40,000 at room temperature for the 480 °C-annealed sample and maintains a value of 19,000 at 450 °C for the 540 °C-annealed one, respectively.