Photoemission and Inverse Photoemission Studies of La Adatom Interactions with YBa2Cu3O6.9

Y. GAO; T.J. WAGENER; C.M. ALDAO; I.M. VITOMIROV; J.H. WEAVER

JOURNAL OF APPLIED PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 1988 vol. 64 p. 1296 - 1300

0021-8979

The surface reactions that occur when adatoms of La are deposited onto the high-temperature superconductor YBaZCu30 6,9 have been studied using high-resolution synchrotron radiation photoelectron spectroscopy and inverse photoelectron spectroscopy. These adatoms lead to the depletion of oxygen from the substrate as La-O forms at low coverage. The process of oxygen withdrawal quickly becomes kinetically limited as the thickening overlayer impedes mass transfer. At the same time, Cu atoms released from the disrupted, no-Ionger-superconducting substrate out diffuse into, and segregate to the top of, the growing La overlayer. The complex reacted interface, therefore, exhibits phases which are likely to be superconducting, insulating, and metallic.