Thermodynamic and diffusion studies on solid (Li,Mg) and (Li,Cd) alloys

• Published in: Materials research bulletin 1984-01, Vol.19 (9), p.1141-1147
• Main Authors: Langen, G., Schwitzgebel, G., Ruppersberg, H.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Metals, semimetals and alloys; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Physics; Specific materials; Thermal properties of condensed matter; Thermal properties of crystalline solids; Thermodynamic properties
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/0025-5408(84)90064-3

By use of electrochemical cells the Li-activity and the inter-diffusion coefficients of solid (Li,Mg) alloys and of the solid phase ‘LiCd’ were measured between 768 K and 800 K. In ‘LiCd’ Darken's excess stability exhibits a maximum at xLi = 0.4 which is much sharper than in the liquid phase. In liquid and solid (Li,Mg) the deviations of a Li from Raoult's law are similar. The mutual diffusion coefficients are large in (Li,Mg) (10 −6cm 2s −1) and extremely large in ‘LiCd’ (10 −4cm 2s −1; the difference is probably due to a high concentration of Li-vacancies in ‘LiCd’, which has been found to be a common feature of Li alloys with NaTl structure. The reduced diffusion coefficients vary less with concentration than the mutual diffusion coefficients.