Local structure and electronic-charge distribution at the rare-earth site of compounds (Gd[sub 1[minus][ital x]R[ital x]])[sub 2]CuO[sub 4], [ital R]=Pr, Nd, Sm, and Eu
- Kernforschungszentrum Karlsruhe, Institut fuer Nukleare Festkoerperphysik, P.O. Box 3640, W-7500 Karlsruhe (Germany)
Mixed compounds (Gd[sub 1[minus][ital x]R[ital x]])[sub 2]CuO[sub 4], [ital R]=Pr, Nd, Sm, and Eu, with [ital T][prime] structure, were studied by x-ray diffraction and by [sup 155]Gd Moessbauer spectroscopy. Structural parameters (unit cell volume, [ital c]/3[ital a]) differ considerably for compounds with different rare earths. In contrast, the variation of the isomer shift [delta][sub [ital I][ital S]] and of the electric-field gradient [ital V][sub [ital z][ital z]] at [sup 155]Gd nuclei with Gd concentration is practically identical in the systems with Pr, Nd, and Sm. These results demonstrate that [delta][sub [ital I][ital S]] and [ital V][sub [ital z][ital z]] in the compounds [ital R][sub 2]CuO[sub 4] are primarily determined by contributions of the local electronic-charge distribution at the rare-earth site, which depends weakly upon the positions of the ions as determined by the structural parameters. Furthermore, our results indicate the possibility of an influence of the degree of covalency upon the transition temperature [ital T][sub [ital c]] achieved in Ce-doped compounds.
- OSTI ID:
- 5528536
- Journal Information:
- Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 48:1; ISSN PRBMDO; ISSN 0163-1829
- Country of Publication:
- United States
- Language:
- English
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ALLOYS
CERIUM ADDITIONS
CERIUM ALLOYS
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
COVALENCE
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
EUROPIUM COMPOUNDS
EUROPIUM OXIDES
EVEN-ODD NUCLEI
GADOLINIUM 155
GADOLINIUM COMPOUNDS
GADOLINIUM ISOTOPES
GADOLINIUM OXIDES
HIGH-TC SUPERCONDUCTORS
INTERMEDIATE MASS NUCLEI
ISOTOPES
LATTICE PARAMETERS
MOESSBAUER EFFECT
NEODYMIUM COMPOUNDS
NEODYMIUM OXIDES
NUCLEI
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PRASEODYMIUM COMPOUNDS
PRASEODYMIUM OXIDES
RARE EARTH ADDITIONS
RARE EARTH ALLOYS
RARE EARTH COMPOUNDS
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SAMARIUM COMPOUNDS
SAMARIUM OXIDES
SCATTERING
STABLE ISOTOPES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TEMPERATURE RANGE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
X-RAY DIFFRACTION