A model is proposed to obtain expressions for thermodynamic functions like the heat of mixing (HM), excess specific heat ( Delta CP), volume of mixing (VM) and isothermal compressibility ( chi T) of liquid binary alloys with a strong compound-forming tendency in order to cover a large range of temperature. This has been used to analyse the temperature dependence of the free energy of mixing (GM), H M and Delta CP for liquid Li-Sn alloys. The specific heat of the liquid Li7Sn2 alloy has been determined experimentally by drop calorimetric heat content measurements and is found to support the theoretical value, which is based on EMF analysis. The results indicate self-coordination towards the Sn-rich end and strong hetero-coordination in the region 0.33<or=cLi<or=1.0, being maximum around Li3Sn. The influence of the chemical short-range order (CSRO) on the concentration fluctuations, Scc(0), chemical diffusion, D, and order parameter, alpha 1, has been considered. Scc(0) registers a dominant temperature effect in the self-coordinated region, whereas the effect of temperature on the diffusion coefficient is most visible in the hetero-coordinated region.
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials