), ▁the ▁first ▁family ▁of ▁rare - ear th ▁magnet s ▁invent ed , ▁are ▁less ▁used ▁than ▁ne od ym ium ▁magnet s ▁because ▁of ▁their ▁higher ▁cost ▁and ▁lower ▁magnetic ▁field ▁strength . ▁ ▁However , ▁sam arium – c ob alt ▁has ▁a ▁higher ▁Cur ie ▁temperature , ▁creating ▁a ▁n iche ▁for ▁these ▁magnet s ▁in ▁applications ▁where ▁high ▁field ▁strength ▁is ▁needed ▁at ▁high ▁operating ▁temper atures . ▁They ▁are ▁highly ▁resist ant ▁to ▁ox id ation , ▁but ▁s inter ed ▁sam arium – c ob alt ▁magnet s ▁are ▁brit t le ▁and ▁pr one ▁to ▁ch ipping ▁and ▁crack ing ▁and ▁may ▁f ract ure ▁when ▁subject ed ▁to ▁thermal ▁shock . ▁ ▁Ne od ym ium ▁▁ ▁Ne od ym ium ▁magnet s , ▁invent ed ▁in ▁the ▁ 1 9 8 0 s , ▁are ▁the ▁strong est ▁and ▁most ▁afford able ▁type ▁of ▁rare - ear th ▁magnet . ▁ ▁They ▁are ▁made ▁of ▁an ▁al loy ▁of ▁ne od ym ium , ▁iron , ▁and ▁bor on ▁( N d 2 Fe 1 4 B ), ▁sometimes ▁abbre vi ated ▁as ▁N IB . ▁▁ ▁Ne od ym ium ▁magnet s ▁are ▁used ▁in ▁numerous ▁applications ▁requiring ▁strong , ▁compact ▁permanent ▁magnet s , ▁such ▁as ▁electric ▁mot ors ▁for ▁cord less ▁tools , ▁hard ▁disk ▁drives , ▁magnetic ▁hold down s , ▁and ▁j ew el ry ▁clas ps . ▁They ▁have ▁the ▁highest ▁magnetic ▁field ▁strength ▁and ▁have ▁a