Cu-induced surface disruption of La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/
Interface reactions for vapor-deposited Cu on La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ were investigated with x-ray photoemission and inverse photoemission. Strong Cu-O reactions indicate oxygen removal and the Cu 2p/sub 3/2/ emission shows conversion of the superconductor Cu/sup 2+/ configuration to Cu/sup 1+/ within 40--50 A of the surface. Valenc-band results show a loss of the Cu 3d/sub x//sub <2/-y/sup =/--O 2p/sub x//sub ,//sub y/ electronic states near the Fermi level, and we conclude that the surface layer is not superconducting. Changes in the occupied empty electronic states of La at low Cu coverages provide additional evidence of Cu-induced reaction. A metallic overlayer begins to form at approx.2 A nominal Cu coverage as these surface reactions become diffusion limited at room temperature.
- Research Organization:
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455
- OSTI ID:
- 5741288
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 37:1; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL BONDS
COATINGS
COLLISIONS
COPPER
COPPER COMPOUNDS
COPPER OXIDES
DEPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRONIC STRUCTURE
ELEMENTS
EMISSION
INTERFACES
IONIZING RADIATIONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
MEDIUM TEMPERATURE
METALS
OXIDES
OXYGEN COMPOUNDS
PHOTOEMISSION
RADIATIONS
RARE EARTH COMPOUNDS
SECONDARY EMISSION
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X RADIATION