Influence of heat treatment on the structural and magnetic characteristics of (NdxPr1-x)(2)Fe14B-based magnetic material for low-temperature application

Abstract

Sintered Pr-Nd-Fe-B-based permanent magnets with 10 and 13 wt. % of Pr were prepared by traditional technology and then subjected to various heat treatments. Stoichiometric composition of the matrix grains corresponds to (Pr0.3Nd0.7)2Fe14B and (Pr0.4Nd0.6)2Fe14B compounds, respectively. Conducted thermomagnetic analysis to samples of these magnets showed the presence of spin-reorientation transition in temperature 95 and 75 K, respectively. This makes the magnet potentially applicable for low temperatures. For these compounds, we have determined the optimum heat-treatment conditions. The magnetic domain structure of the magnet subjected to an optimum heat treatment has been studied. The effect of different low-temperature heat treatments on the magnetic properties of magnets has been demonstrated.