Origin of the asymmetric spinodal decomposition in the Al-Zn system - art.no. 020101

The Fermi surface and the phase equilibria in the Al-Zn system are studied theoretically in the framework of the density-functional theory, linear muf fin-tin orbital method, and the Green's function technique. Analyzing the F ermi surfaces of the random alloys, we find a series of electronic topologi cal transitions within the stability range of the fcc solid solution. A rel ation between these transitions and the phase stabilities of fee Al-Zn is e stablished. We show that the asymmetry of the miscibility gap as well as of the mixing energy are due to the electronic topological transitions in the system.