Magnetic properties of misch-metal partially substituted Nd–Fe–B magnets sintered by dual alloy method**Project supported by the National Natural Science Foundation of China (Grant No. 51590880), the National Key Research and Development Program of China (Grant Nos. 2014CB643702 and 2016YFB0700903), Key Research Program of the Chinese Academy of Sciences of China, and the Inner Mongolia Science and Technology Major Project of

Abstract

The misch-metal (MM) partially substituted Nd–Fe–B sintered magnets were fabricated by the dual alloy method, and the crystal structure, microstructure, and magnetic properties were analyzed comprehensively. X-ray diffraction (XRD) reveals that the increasing content of the MM has an inconsiderable effect on the crystallographic alignment of the magnets. Grains of the two main phases are uniformly distributed, and slightly deteriorate on the grain boundary. Due to the diffusion between the adjacent grains, the MM substituted Nd–Fe–B magnets contain three types of components with different Ce/La concentrations. Moreover, the first-order reversal curve (FORC) diagram is introduced to analyze the magnetization reversal process, coercivity mechanism, and distribution of reversal field in magnetic samples. The analysis indicates that there are two major reversal components, corresponding to the two different main phases. The domain nucleation and growth are determined to be the leading mechanism in controlling the magnetization reversal processes of the magnets sintered by the dual alloy method.