AVS 54th International Symposium | |
Surface Science | Tuesday Sessions |
Session SS-TuP |
Session: | Surface Science Poster Session |
Presenter: | L. Huerta, Universidad Nacional Autónoma de México |
Authors: | L. Huerta, Universidad Nacional Autónoma de México R. Escamilla, Universidad Nacional Autónoma de México E. Regalado, Universidad Nacional Autónoma de México M. Flores, Universidad de Guadalajara, México |
Correspondent: | Click to Email |
X-ray photoemission spectroscopy (XPS) and Ultraviolet photoemission spectroscopy (UPS) are used to compare the electronic structures of ZrB2 and ZrB12. The Zr 3d and B 1s core levels associated with the chemical states of ZrB2 and ZrB12 were identified, the Zr 3d core level shows a spin-orbit split 3d5/2 and 3d3/2 while that the B 1s core levels exhibit a single asymmetric peak typical of a metallic boride. Comparing with Zr metallic, boron and ZrO2 reference materials, for ZrB2 we observed a positive chemical shift for B 1s and a negative chemical shift for Zr 3d3/2 while that in ZrB12 the chemical shift in B 1s and Zr 3d3/2 is inverse, suggesting that a some charge transfer occurred from the Zr atoms to the B atoms in the ZrB2 and from the B atoms to the Zr atoms in ZrB12. The measured valence bands using UPS and XPS are consistent with band-structure calculations indicating a higher density of states (DOS) at EF for ZrB12 compared to ZrB2. That’s suggesting that the Tc in ZrB12 is due to B 2p and Zr 4d-derived DOS at EF.