NdFeB magnets with zero temperature coefficient of induction

Temperature compensation for the induction of NdFeB type magnets has been investigated. A computer assisted alloy selection method was adopted to identify composition of zero temperature coefficient of induction over -50 to 200°C. Selected alloys were processed into magnet by the conventional powder metallurgy method. The experimental temperature coefficient on the sintered magnet correlated with the prediction satisfactory. Holmium is an essential ingredient required for temperature compensation of NdFeB magnets. A magnet, (Nd0.23Ho0.64Dy0.13)15Fe79B6with Brof 7,700 Gauss, Hcof 7,700 Oe, Hciof 20,600 Oe, BHmaxof 14.8 MGOe and temperature coefficient of -0.029% per °C over -50 to +150 was obtained.