Fe-based nanocrystalline soft magnetic alloys for high-temperature applications

Abstract

We report on improved high-temperature soft magnetic properties in Fe88−2xCoxNixZr7B4Cu1 nanocrystalline alloys. Substituting 5.5 at. % Co and Ni for Fe enhances the magnetization by 5% at ambient temperature and by 30% at 650 °C. The Curie temperature of the residual amorphous phase is also raised significantly (from 67 °C for x=0 to 298 °C for x=5.5), resulting in low coercivities (<30 A m−1) for Fe77Co5.5Ni5.5Zr7B4Cu1 over the temperature range 50–500 °C. The higher magnetization and Curie temperature as compared with other Fe-based alloys, and smaller Co content as compared with (Fe,Co)-based alloys, make this alloy attractive as an affordable high-temperature soft magnetic material.

Optimization of the refrigerant capacity in multiphase magnetocaloric materials

“…22,23 The two phases ͑Fe 66 Co 11 These calculated results were verified experimentally by preparing a laminate composite ͑layers of melt-spun ribbon pieces of the two compositions in intimate contact͒ corresponding to x = 0.643. The experimental RCI AREA is 36%, in excellent agreement with the predictions based on the simulated composite.…”

Magnetocaloric effect and critical exponents of Fe77Co5.5Ni5.5Zr7B4Cu1: A detailed study

“…Further details about sample preparation, microstructure, and magnetic characterization are given elsewhere. 17 The change in magnetic entropy caused by a variation in applied magnetic field has been obtained by the numerical approximation of…”

Characterization of the magnetic interactions of multiphase magnetocaloric materials using first-order reversal curve analysis

“…Further details about sample preparation, microstructural, and magnetic characterization are given elsewhere. 10 Composite samples were prepared by putting two ribbons of different compositions in mechanical contact, keeping them together inside the sample holder. This resembles the method used for the measurement on the magnetocaloric response (layered combinations of pieces of the different alloys).…”