<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>k</mml:mi></mml:math>-dependent exchange splitting of empty bands in nickel

Abstract

Spin-polarized inverse photoemission spectroscopy has been used to study the spin-dependent unoccupied electronic structure of nickel. Measurements involved the study of Ni(110) in the $\overline{\ensuremath{\Gamma}Y}$ azimuth. A $k$-dependent spin splitting with measured spectral values ranging from $113\ifmmode\pm\else\textpm\fi{}20\mathrm{meV}$ to $337\ifmmode\pm\else\textpm\fi{}51\mathrm{meV}$ has been resolved for a bulk $\mathrm{sp}$-like band. These results are consistent with differential $sp/d$ hybridization. Furthermore, an exchange splitting of $190\ifmmode\pm\else\textpm\fi{}30\mathrm{meV}$ is detected for a Shockley surface state. The experimental observations are in good agreement with calculations employing one-step theory.