Abstract
Photoemission results are presented for recrystallized Nb foils and for chemisorbed hydrogen on Nb. A split-off bonding orbital due to adsorbed H is observed below the d bands. The temperature dependence of this photoemission feature above 300 K and the kinetics of its growth and saturation suggest that H may exist in two quite different states near the surface of Nb. The interpretation of these results as they relate to recent measurements of hydrogen uptake in Nb is also discussed.