The effects of CeFe2 phase distribution and magnetic transition on the magnetic behavior of hot-deformed Ce16Fe76Cu2B6 magnet

Abstract

Tailoring the high-melting-point CeFe2 phase is an effective strategy for optimizing the magnetic performance of Ce–Fe–B permanent magnets. Further property enhancement can also be achieved by modifying the distribution, morphology, and magnetic state of the grain-boundary phases. In this study, Cu addition was employed to promote the formation of a thin network-like CeFe2 phase in hot-deformed Ce16Fe76Cu2B6 magnets. The effects of the CeFe2 magnetic transition on the magnetic properties and magnetization behavior were investigated. The results show that the saturation magnetization and maximum energy product of the magnet are significantly enhanced below 200 K. Quantitative analysis reveals that a substantial part of this enhancement is attributable to the increased magnetization and remanence due to the transformation of the CeFe2 phase from paramagnetic to ferromagnetic as the temperature decreases. Henkel plots and first-order reversal curve analyses confirm that the magnet exhibits single-phase-like behavior of magnetization and the demagnetization process is dominated by the Ce2Fe14B phase, indicating well exchange coupled soft magnetic CeFe2 phase and hard magnetic Ce2Fe14B phase at the temperature below 200 K. The average interaction field effectively suppresses premature demagnetization of CeFe2 and ensures stable magnetic coupling. This work can help to understand the effects of CeFe2 phase distribution and magnetism on the performance of Ce–Fe–B based permanent magnets.