Influence of additional nanoparticles on coercivity of sintered Nd–Fe–B magnets

Nguyen Van Duong, Pham Thi Thanh, Nguyen Hai Yen, Nguyen Mau Lam, Nguyen Huy Ngoc, Duong Dinh Thang, Nguyen Le Thi, Nguyen Hoang Ha, Dinh Huu Quang, Nguyen Cong Ngoc and Nguyen Huy Dan

Abstract

In this work, we investigated the influence of concentration of the additional nanoparticles of Dy₄₀Nd₃₀Al₃₀ and Nd₃₀Al₃₀ on the coercivity of the sintered Nd_16.5Fe₇₇B_6.5 magnets. Composition and concentration of the additional compounds clearly influence magnetic properties of the magnets. The coercivity (H_C) increases linearly from 8 kOe  to 13 kOe with increasing the weight fraction of the Dy₄₀Nd₃₀Al₃₀ nanoparticles from 0 to 5%. Meanwhile, the H_C of the Nd₃₀Al₃₀ added magnets reaches a maximal value of 10 kOe  at the optimum addition of 3 wt%. The quite high maximum energy products, (BH)_max > 30 MGOe, were also obtained for the magnets added with the nanoparticles