A BAND-STRUCTURE VIEW OF THE HUME-ROTHERY ELECTRON PHASES

The stability of Hume-Rothery's electron phases is studied using moder n bandstructure techniques. For these alloys, empirical evidence has s hown a strong correlation between the number of valence electrons per atom and the adopted crystal structure. The generally accepted explana tion traces the phenomenon to prominent structure in the electron dens ity of states which arises when the free-electron Fermi sphere encount ers the Bragg planes at the surface of the Brillouin zone. By applying a rigid band model on the basis of density functional theory to the a rchetypal system Cu-Zn, we obtain accurate density-of-states functions which are used to critically evaluate the popular models due to Mott and Jones. We also are able to account for the stability of the gamma- phase.