Origin of the Ba core-level binding-energy difference between tetragonal and orthorhombic
- 1 February 1991
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review B
- Vol. 43 (4), 3695-3698
- https://doi.org/10.1103/physrevb.43.3695
Abstract
Sintered bulk samples of the orthorhombic, superconducting, phase of exhibit a ≃1.5 eV Ba core-level decrease compared to the tetragonal, nonsuperconducting phase. This is also observed for thin-film material in the two phases. Using ab initio cluster calculations, we show that shifts of this magnitude are explainable by isotropic contraction of the Ba-O bond length in the 0.01- to 0.02-Å range, values compatible with the known lattice-parameter changes between the phases. Finally, even in situ cleaved good-quality single crystals of the orthorhombic phase show a chemically shifted Ba component for some regions of the surface, which may be due to Ba-O bond-length contractions at the surface-vacuum interface.
Keywords
This publication has 14 references indexed in Scilit:
- Core and valence XPS spectra of clean, cleaved single crystals of YBa2Cu3O7Journal of Electron Spectroscopy and Related Phenomena, 1990
- A bibliography for high energy spectroscopy studies of high-Tc superconductors (1987–1989)Physica C: Superconductivity and its Applications, 1990
- Surface and mixed valence effects in XPS spectra from YBCOPhysica C: Superconductivity and its Applications, 1989
- Ba 4d core-level spectroscopy in the high- superconductor: Existence of a surface-shifted componentPhysical Review B, 1989
- The hole concentration on oxygen sites in the highT c superconductor Y1?Ba2?Cu3?O7?xZeitschrift für Physik B Condensed Matter, 1988
- Electronic structures of the surface and its modification by sputtering and adatoms of Ti and CuPhysical Review B, 1988
- ARXPS-studies of?-axis textured ? superconducting YBa2Cu3O x -filmsZeitschrift für Physik B Condensed Matter, 1988
- Core-level shifts on cleavedYBa2Cu3O7−x(001) surfaces observed in angle-resolved photoemissionPhysical Review B, 1988
- Oxygen defect in : An x-ray photoemission approachPhysical Review B, 1988
- Photoemission on the highT c superconductors Y?Ba?Cu?OZeitschrift für Physik B Condensed Matter, 1987