Metastable Phase Formation in Be-Nb Intermetallic Compounds

Abstract

ABSTRACTAmorphous structures or metastable crystalline phases are produced in sputter deposited Be-Nb alloys (5–15 at.% Nb) depending on the substrate temperature. The metastable phases transform to the stable Be12Nb, Be17Nb2 or Be3Nb phases on annealing at temperatures >800°C. No Be5Nb phase was found and the Be17Nb2 phase is stable to low temperature. The Be12Nb phase appeared to have a stoichiometric range of about 5.5 to 7.7 at.% Nb. The formation of the metastable phases is consistent with current models and theories.