Electronic structure and sign reversal of the Hall coefficient in amorphous CuZr alloys

Abstract

We present calculated densities of states (DOS) for ${\mathrm{Cu}}_{\mathrm{x}}$ ${\mathrm{Zr}}_{1\mathrm{-}\mathrm{x}}$ amorphous alloys across the compositional range. We find that for x<80 at. % Cu there is no ordering and the Fermi level $E_F$ is dominated by the Zr 4d subband, while above 80 at. % Cu the local order increases and the DOS at $E_F$ abruptly decreases and is dominated by the s states. These changes in DOS and the fact that the energy derivative of the self-energy changes its sign (implying a change of sign of the Fermi velocity) gives further insight into the experimentally observed sign reversal of the Hall coefficient which occurs for 80≤x≤85 at. % Cu.