Experimental energy dispersions for valence and conduction bands of palladium

Abstract

Using angle-resolved photoemission with synchrotron radiation, we have determined accurate energy-versus-momentum dispersion relations along the 111 direction using a Pd(111) crystal. The energy E ( 0.1 eV accuracy) and the momentum parallel to the surface k are measured directly. The perpendicular component of the momentum k→ is obtained from the measured final energy via a calculated free-electron-like final band that is found to be accurate within ±5% of the zone-boundary momentum by comparison with certain critical points that have been measured directly (L1, G'2, and G15). For the initial bands, we find the dispersions of the two d-like 3 bands and of the sp-type ?1 band. Measured critical points (in eV) for bands numbered with increasing energy are: G2,3,4=-2.55±0.15, G5,6=-1.15±0.1, G7=18.4±0.5, G8=21.7±0.5, L4=-0.4±0.2, L5-0.1±0.1, and L7=7.7±0.3. Spin-orbit splitting ( 0.4 eV maximum) is observed for the upper 3 band. © 1978 The American Physical Society.