Volume change in Zr50Cu40Al10 glassy alloys

Quaternary Zr47Cu40Al10M3 (M: IVA ∼ VIA), Zr50Cu37Al10M3 (M: VIIA ∼ IB), and Zr50Cu40Al7M3 (M: IIB∼) bulk glass alloys (BGAs) were examined to clarify the glassy structure of Zr50Cu40Al10 BGA. The glass structural difference was evaluated by the volume change due to structural relaxation at the glass-transition temperature (Tg); the volume shrinkage was estimated using density measurement. The results indicated that Pd, Ag, Pt, and Au, which are characterized by a filled d-shell electron structure, are effective for enhancing volume expansion in a glass structure. Furthermore, the volume changes in quaternary Zr–Cu–Al–M BGAs could be classified into two groups. This implies a difference in glass structure between the Zr50Cu37Al10M3 (M = Pd, Ag, Pt, and Au) BGA and others examined in this study.