Answer: niobiums

AnswerCrossword Clue
niobiumssteel-gray metallic element resembling tantalum in its chemical properties; becomes a superconductor below 9 K; used chiefly in alloy steels. Symbol: Nb; at. no.: 41; at. wt.: 92.906; sp. gr.: 8.4 at 20┬░C
niobiumsNIOBIUM, a metallic element