Magnetic and microstructural properties of (Nd,Pr)-(Tb,Dy,Gd)-(Fe,Co,Al,Cu)-B type magnets

摘要

(Nd,Pr)-(Tb,Dy,Gd)-(Fe,Co,Al,Cu)-B magnets were heat treated in two different ways and investigated in the temperature range 4.2 to 400 K. After optimal heat treatment intrinsic coercive field _iH_c = 1640 and 5040 kA/m for room temperature and 10 K was obtained and the temperature coefficient of remanence α = -0.01 for temperature range 80 to 375 K was found. On basis of magnetic measurements and ~(57)Fe Moessbauer spectroscopy, the possible reasons for the increase of _i H_c during multi-step heat treatment are discussed.