Thermodynamic properties of CdNa alloys

The alloying behaviour of CdNa alloys is discussed on the basis of a simple theory based on the complex formation model. Though Cd and Na are simple metals but CdNa alloys exhibit anomalous behaviour. The excess free energy of mixing is negative in the region 0.6 ≤ C_Na > 0.1 and thereafter becomes positive. The concentration-concentration fluctuations in the long wavelength limit Scc(0) is larger than the ideal values Scc(0,id) up to C_cd = 0.55 and is less than ideal values for C_cd > 0.55. The concentration-dependent nature of asymmetry of the thermodynamic properties of mixing have been explained in this paper. The study reveals that Cd₂Na complex exists in the liquid phase close to melting temperature.