Experimental investigation of phase equilibria in the Sn–V–Zn system at 450 °C and 600 °C

Highlight
• The phase equilibria of the Sn–V–Zn system were experimentally determined.
• Two new ternary compounds, V7Sn12Zn40 and τ, were found.
• V7Sn12Zn40 has a bcc structure with a lattice parameter a = 2.54919 nm.
• The solid solubilities of the third element in binary compounds were measured.

The 450 °C and 600 °C isothermal sections of the Sn–V–Zn ternary phase diagram were experimentally determined using X-ray diffraction and scanning electron microscopy coupled with energy/wave dispersive spectroscopy. All the three-phase equilibria were well determined. Two new ternary compounds, V7Sn12Zn40 and τ, were found in the system. V7Sn12Zn40 had a cubic structure with a lattice parameter a = 2.54919 nm. Its composition range spanned from 12.2–13.7 at.% V, 21.9–25.7 at.% Sn and 60.6–65.9 at.% Zn. And the composition range of τ was 11.1–11.6 at.% V, 13.2–15.8 at.% Sn and 72.6–75.7 at.% Zn. DTA results indicated that V7Sn12Zn40 and τ can stably exist below 509.6 °C and 501.5 °C, respectively. Moreover, the maximum solubilities of Zn in VSn2 and V3Sn were measured to be 2.6 at.% and 7.7 at.%, respectively. While Sn had no detectable solubility in Zn–V compounds.