Neo magnets were developed by Hitachi in 1980’s. They are also called Neodymium Boron Iron magnets or NdFeB magnets. They are produced by sintering ~4µm size fine powders. They can be made only in simple blocks, ring or arc shapes. They are made of ~66% Fe, 30% Neo, 1% B,0.7% Nb, 0.3% Al. 7 to 12% dysprosium is added to improve high temperature performance, but it increases their cost. Neo magnets have poorer thermal stability than SmCo magnets (~0.1%/C). So currently most engineers prefer to use them below 150C. It can corrode easily, so needs coatings. Their energy product ranges 28 to 54 MGOe. Their residual flux density ranges 1 to 1.45T. Their maximum service temperature ranges 80 to 250C.
PMAG Database Folder AM for Neodymium Magnets lists 3351 B(H) Demagnetization Curves of 707 grades, produced by more than 35 manufacturers worldwide. For names of all these grades, please click on PMAG, Materials.