Magnetic field annealing of FeCo-based amorphous alloys to enhance thermal stability and Curie temperature

Annealing temperatures and applied magnetic fields are two important parameters for the performance modification of magnetic alloys. This article investigated the effect of different annealing temperatures on crystallization condition, magnetic properties and thermal stability of the amorphous magnetic alloy Co 36 Fe 36 Si 4.8 B1 9.2 Nb 4 (at%). Results indicate that the annealing temperature can significantly affect the size and content of precipitated nanocrystals in the amorphous alloy, and the precipitation of nanocrystalline phases can result in the distinct change of magnetic properties and Curie temperature. When the annealing was performed at 595 °C for 30 min under an applied transverse external magnetic field of 9550.0 A·m −1 , the amorphous alloy shows excellent soft magnetic properties with the saturation magnetization of alloy reaching 110.00 mA·m 2 ·g −1 , the residual magnetic induction intensity of 4 × 10 −6 T and the coercivity as low as 57.3 A·m −1 . Furthermore, the Curie temperature of the field-annealed samples can reach up to 440 °C, approximately 58 °C higher than that of the as-quenched species.