Properties and atomic structure of amorphous early transition metals

Simple correlation between mechanical and thermal properties in TE–TL (TE=Ti,Zr,Hf;TL=Ni,Cu) amorphous alloys

“…Both, our present and literature data [4,5,14,16,[20][21][22][23][24][25] for Young's modulus of TE-TL glassy alloys increase approximately linearly with TL content x (Fig. 1).…”

“…However, the values for θ D of Hf-Cu and Zr-Cu alloys are practically the same, whereas the values of E were larger in the former alloy system. [20,21], Zr-Ni [20,22], Ti-Cu [16,23], Ti-Ni [21], HfCu [16], Hf 34 Cu 66 [4], Zr 36 Cu 64 [24] and Zr 50 Cu 50 [25] alloys vs. Cu,Ni content x. E of pure (α) Ti, Zr and Hf are also shown. The inset: velocity of ultrasonic waves along as-cast and annealed (upper values) ribbons.…”

“…Further, very low extrapolated values of E at x = 0 (well below those for the crystalline phases (hcp) of TEs) indicate weak interatomic bonding in aTEs. Thus, high N(E F ) of a-TEs and TE-rich TE-TL alloys are [16] accompanied with weak interatomic bonding atypical for transition metals. This reflects very different electronic and atomic structures of glassy TE-TL alloys compared to those of crystalline TEs [6,16].…”

“…These new data, combined with literature data enable us to determine accurately the variations of these parameters with TL content over a broad concentration range (including that where BMG form), and thus to observe clearly the effect of change in TE (Ti → Zr → Hf) on these properties (and their correlations) in glassy TE-TL alloys. In spite of similar electronic structures [16] the variations of mechanical, vibrational and thermal stability parameters in Ti-TL alloys differ considerably from those in Zr-TL and Hf-TL alloys. We also discuss the correlation (or lack of) between these properties and the formation of BMGs.…”

“…Since the majority of results for TE-TL glassy alloys have been obtained for Zr-TL alloys, this method yielded reliable value of N(E F ) [6], atomic volume [9] and magnetic, superconducting, mechanical and thermal parameters of a-Zr [14,15]. A recent study of Hf-TL glassy alloys [13] enabled us to obtain the estimates for selected parameters of all a-TEs [16]. These parameters were found to agree well with those calculated for face-centered cubic phase of TE metals [17] and were quite different from those of stable crystalline phases (hcp) of TEs.…”