Magnetic after-effect in FeNiZrCuB amorphous alloys

Abstract

The magnetic after-effect (MAE) and AC susceptibility in the amorphous Fe 86 − x Ni x Zr 7Cu 1B 6 alloys with different contents of Ni ( x = 0–86 at%) were investigated. The Curie temperatures T c were estimated from the temperature dependences of the AC susceptibility measured in the temperature range 20–550°C. Additions of Ni up to x = 43 at% cause rapid increase of the Curie temperature from 71°C for Fe 86Zr 7Cu 1B 6 to 373°C for Fe 43Ni 43Zr 7Cu 1B 6 alloys. Higher concentrations of Ni cause decrease of T c down to paramagnetic state of Ni 86Zr 7Cu 1B 6 alloy at the room temperature. It was found that the additions of Ni drastically change shapes and amplitudes of MAE spectra. From the MAE spectra measured in the temperature ranges (− 197°C; T c) the activation energy spectra with the most probable value Q = 1.23 eV were obtained.