| Abstract: | RE2 Fe14B-based (RE,rare earth) permanent magnets containing abundant and cheap La/Ce have attracted intense attention recently.In comparison with Ce that can fully replace Nd in the 2∶14∶1 lattice,La substitution for Nd has long been limited at a low level.Here we present that through doping La35Ce65 alloy with the La/Ce ratio in natural mineral,stable 2∶14∶1 phase can be maintained at 1273 K within the entire substitution range of(La35Ce65)x(Pr20Nd80)1-x]2.14Fe14B (0.6 ≤ x ≤ 1.0,at.％),as verified by composition analysis,microstructural characterization and magnetic measurements.Interestingly,the promoted La solution in 2∶14∶1 phase induces two unique findings upon coexisting La-Ce-Pr-Nd: i) Compared to Ce that fits well with the nominal concentration,La deviates noticeably from the nominal one;ii) Nanoscale spinodal-decomposition-like phase separation is observed due to different solubilities of La-Ce-Pr-Nd elements in 2∶14∶1 phase.Above joint effects induce higher Curie temperature than estimation based on the rule of mixture,which delights the prospect of La35Ce6s alloy in developing low-cost permanent materials. |
