A valence band photoemission study of a Tl-2212 superconducting single crystal

A good quality single crystal of T1-2212 superconductor has been studied us ing ultra-violet photoemission. Our results show some of the finer features of the valence band of T1-2212, which were in a qualitative agreement with the calculations based on local density approximation-full-potential linea rized augmented plane wave (LDA-FLAPW). We also see the presence of a well- defined Fermi edge in our sample and an enhancement of the O 2p states due to the oxygens in and out of the Cu-O plane showing an increased density of holes in the superconducting state. The results are discussed in light of the reported local structural changes associated with the superconducting t ransition in high Te perovskites. (C) 1999 Elsevier Science B.V. All rights reserved.