Comparative study of the electronic structure of MgB2 and ZrB2
Abstract
X-ray photoemission spectroscopy is used to compare the electronic structures of MgB2 and ZrB2. The B 1s core levels in high-quality MgB2 and ZrB2 exhibit a single asymmetric peak typical of a metallic boride. The Mg 2p core level shows a single peak with negligible intensity in charge-transfer satellites and no correlation effects. The Mg 2p and B 1s core-level spectra exhibit a broad bulk plasmon feature centered at about 22 eV from the main peak, in good accord with calculations. The measured valence bands are consistent with band-structure calculations indicating a higher density of states (DOS) at EF for MgB2 compared to ZrB2. The high Tc in MgB2 is due to p-derived DOS, while ZrB2 is dominated by d-derived states at EF.
- Publication:
-
Physical Review B
- Pub Date:
- November 2003
- DOI:
- 10.1103/PhysRevB.68.174506
- Bibcode:
- 2003PhRvB..68q4506J
- Keywords:
-
- 74.25.Jb;
- 74.25.Kc;
- 79.60.Bm;
- Electronic structure;
- Phonons;
- Clean metal semiconductor and insulator surfaces