Calorimetric study of the Li-Zn system

- The enthalpy of solution of liquid Zn in liquid Sn.
- Preparation and identification of the Li-Zn intermetallic phases.
- Enthalpy of formation of αLiZn, αLi2Zn3, αLiZn2, αLi2Zn5, αLiZn4 phases.
- Comparison with the Miedema model.

The solution calorimetry method was applied to determine the standard formation enthalpy of the solid intermetallic phases: LiZn, Li2Zn3, LiZn2, Li2Zn5, LiZn4 and the heat of solution of zinc in liquid Sn. These alloys were prepared from pure metallic Li and Zn, which were melted in a glove-box, filled with high purity argon with a very low concentration of impurities. All experiments were performed with the use of Setaram MHTC 96 Line evo calorimeter. The heat of zinc solution in Sn-bath in the temperature range 723-926 K was equal on average to (8.6 ± 0.3) kJ·mol−1. The standard formation enthalpy of the solid alloys, with concentrations corresponding to LiZn, Li2Zn3, LiZn2, Li2Zn5, LiZn4 intermetallics, was measured at 723 K. The values of the standard formation enthalpy were estimated as {(−15.3 ± 0.5), (−16.3 ± 0.4), (−15.6 ± 0.3), (−15.3 ± 0.3), (−12.3 ± 0.2)} kJ·mol−1 at., for the LiZn, Li2Zn3, LiZn2, Li2Zn5, LiZn4, respectively. They were compared with the data calculated by means of the Miedema model.