Abstract
Surface chemical states were studied for Zr and Nb metals exposed to 8-keV hydrogen molecular ions. X-ray photoemission spectroscopy (XPS) measurements revealed that chemical shifts of the binding energies for the ion-implanted Zr from the metallic states are 0.6–1.4 eV, consistent with the core-line shifts for thermally synthesized . In the case of the ion-implanted Nb, the corresponding shifts are 0.6–0.8 eV, in good agreement with those for thermally synthesized . On the other hand, the ion implantation provided XPS spectra with a distinct photopeak attributable to a metal 4d–H 1s bond near the Fermi level, 3.4 eV for Zr and 4.6 eV for Nb, respectively. The peak positions are ∼2.5 eV lower than those calculated previously for the dihydrides. The photopeaks grew upon thermal annealing to 610 °C. The observations are discussed in relation with the peculiarity of hydrogen sites in the crystal lattice and partial recovery of the ion-induced surface damage.
- Received 23 July 1984
DOI:https://doi.org/10.1103/PhysRevB.31.791
©1985 American Physical Society