Occupied density of states in MgB2 revealed by photoemission microscopy -: art. no. 132503

Using photoemission microscopy at submicron lateral resolution, we measured the occupied density of states in MgB2 single crystalline grains from commercial MgB2 powder. This experiment provided a reliable measurement of the integrated density of states in MgB2 directly comparable to the theoretical predictions. According to the conventional metallic nature of MgB2, with weak electron-electron correlation effects, we observe a close overall agreement between our photoemission valence-band spectrum and the calculated density of states. This is further supported by the analysis of the loss features in the B 1s photoemission spectrum. We also report evidence of a quick surface degradation due to the exposure to the synchrotron radiation beam.