STRUCTURAL STUDIES OF SOME HIGH-TC SUPERCONDUCTING OXIDES THROUGH XANES AND XPS TECHNIQUES

Some structural investigations have been carried out in case of YBa2Cu 3O7-x and Bi2.2Ca2.1Sr0.7Cu2Oy using XANES as a probe and Cu2O and CuO as reference compounds. While such studies have been performed in ter ms of the pre-edge structure, principal absorption maximum and shoulde r structure beyond the principal absorption maximum, complementary inf ormation obtained from 2p core-level XPS of Cu has been used to ascert ain charge transfer from oxygen 2p states to vacant 3d states of coppe r.