Calculation of electronic density of states for amorphous ZrCu and ZrNi alloys

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Abstract
The author has recently developed a simple scheme based on the recursion method which allows the relative position of the d bands in an amorphous transition-metal alloy to be determined if the average charge transfer is known. To find the hopping integrals the author uses tabulated values of the overlap parameters (dd sigma , dd pi , and dd delta ) obtained from a fit to the bands of the pure metals. This scheme allows a parameterized Hamiltonian to be built to represent the transition-metal alloys, avoiding the need for a detailed fitting of LCAO bands to the bands of a corresponding crystalline compound. In the procedure the overlap parameters are tabulated for the pure metal and charge transfer is either known or neglected. Therefore the results obtained for the density of states of the alloy are well defined and parameter free. Here the author uses the above procedure to obtain the electronic structure of amorphous ZrCu ( alpha -ZrCu) and alpha -ZrNi alloys for two different compositions. The results are compared with those obtained by other methods and with experiment. The calculations are in good agreement with existing UPS and XPS results for these alloys. The values obtained for the density of states at the Fermi level, N(EF), for alpha -ZrCu are also compatible with those inferred from experimental data for melt-spun samples.