Empty and occupied electronic states of CuxY

Abstract

The densities of the unoccupied states of ${\mathrm{Cu}}_{90}$${\mathrm{Y}}_{10}$ and ${\mathrm{Cu}}_{74}$${\mathrm{Y}}_{26}$ alloys have been probed by inverse photoemission in the ultraviolet range and compared with those of pure Cu and Y. This, along with direct photoemission spectra, allows for the determination of $\mathrm{Cu} 3d$- and $\mathrm{Y} 4d$-band energy positions and widths in the joint density of empty and occupied states. From these data an increase of empty $d$-like states along with a resulting decrease of empty $\mathrm{sp}$-like states is revealed as well as a hybridization of the $\mathrm{Cu} 3d$ and $\mathrm{Y} 4d$ levels.