Some crystal chemistry of (Ln,Ce)2CuO4-δ superconductors
Creators
- 1. Melbourne Univ., Parkville (Australia). School of Physics
- 2. Griffith Univ., Brisbane (Australia). Div. of Science and Technology
- 3. Queensland Univ., St. Lucia (Australia). Electron Microscope Centre
Description
Compounds of the form (Ln, Sr, Ce)2CuO4-δ (Ln = rare earth element) crystallise as the Nd2CuO4 structure type, K2NiF4 structure type or perfectly and imperfectly ordered intergrowths of these parent structures. These structurally similar phases exhibit superconductivity in which the charge carriers are holes (in Sr-doped material) or electrons (in Ce doped material). In this study, X-ray Photoelectron Spectroscopy (XPS) and High Resolution Electron Microscopy (HREM) were used to investigate the charge balancing mechanisms operating in each superconducting regime and the structural changes accompanying compositional variation. It was found that under slightly reducing conditions charge coupled cation substitutions predominate, whilst at low pO2 (<10-5 atm) perfectly ordered oxygen superlattices form. The structural and electronic changes which accompany deoxygenation were observed in situ during XPS and HREM observations. 29 refs., 8 figs., 3 tabs
Availability note (English)
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21070500.pdf
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Additional details
Publishing Information
- Imprint Pagination
- 29 p.
- Report number
- UM-P--89/97
INIS
- Country of Publication
- Australia
- Country of Input or Organization
- Australia
- INIS RN
- 21070500
- Subject category
- S36: MATERIALS SCIENCE; S75: CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Numerical Data
- Descriptors DEI
- ANNEALING; CERAMICS; CERIUM OXIDES; CHARGE CARRIERS; COPPER OXIDES; CRYSTAL STRUCTURE; ELECTRON MICROSCOPY; ELECTRON-HOLE COUPLING; EXPERIMENTAL DATA; HIGH TEMPERATURE; HOLE MOBILITY; LANTHANUM OXIDES; NEODYMIUM OXIDES; OXYGEN; PHASE STUDIES; PHOTOELECTRON SPECTROSCOPY; PRASEODYMIUM OXIDES; RADIATION EFFECTS; RARE EARTHS; REDUCTION; SEMICONDUCTOR MATERIALS; STRONTIUM OXIDES; STRUCTURAL CHEMICAL ANALYSIS; SUPERCONDUCTIVITY; SUPERCONDUCTORS; SUPERLATTICES
- Descriptors DEC
- ALKALINE EARTH METAL COMPOUNDS; CERIUM COMPOUNDS; CHALCOGENIDES; CHEMICAL REACTIONS; COPPER COMPOUNDS; COUPLING; DATA; ELECTRIC CONDUCTIVITY; ELECTRICAL PROPERTIES; ELECTRON SPECTROSCOPY; ELEMENTS; HEAT TREATMENTS; INFORMATION; LANTHANUM COMPOUNDS; MATERIALS; METALS; MICROSCOPY; MOBILITY; NEODYMIUM COMPOUNDS; NONMETALS; NUMERICAL DATA; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; PRASEODYMIUM COMPOUNDS; RARE EARTH COMPOUNDS; SPECTROSCOPY; STRONTIUM COMPOUNDS; TRANSITION ELEMENT COMPOUNDS