Probing the electronic and defect structure of perovskite superconductors. [La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/; YBa/sub 2/Cu/sub 3/O/sub 7-d/]
Positions, either localized or delocalized, in the perovskite superconductors are sensitive to changes in electron density accompanying the normal-to-superconducting transition. We have been using this probe in our laboratory to study the nature of this new phenomena. Our work to date, which is briefly reviewed here, has consisted of a series of lifetime studies on La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ and YBa/sub 2/Cu/sub 3/O/sub 7-d/ superconducting samples, the determination of the positron wave function in the /open quotes/perfect/close quotes/ crystal, and a direct measurement of the electron momentum density in single crystal La/sub 2/CuO/sub 4/. Several important observations have resulted from this early work: the similar response of the positron annihilation lifetime to superconductivity in both La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ and YBa/sub 2/Cu/sub 3/O/sub 7/, and a quantitative description of the electronic structure for La/sub 1.85/Sr/sub 0.15/CuO/sub 4/ in terms of a linear combination of atomic orbital-molecular orbital (LCAO-MO) model. 3 figs., 6 refs.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA); Missouri Univ., Kansas City (USA); Houston Univ., TX (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5046446
- Report Number(s):
- UCRL-98070; CONF-880210-1; ON: DE88008349
- Country of Publication:
- United States
- Language:
- English
Similar Records
Temperature and depth dependence of positron annihilation parameters in YBa/sub 2/Cu/sub 3/O/sub 7-. / and La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/
Temperature and depth dependence of positron annihilation parameters in YBa/sub 2/Cu/sub 3/O/sub 7-x/ and La/sub 1. 85/Sr/sub 0. 15/CuO/sub 4/
Related Subjects
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
656002 -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALKALINE EARTH METAL COMPOUNDS
ANNIHILATION
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BARIUM COMPOUNDS
BARIUM OXIDES
BASIC INTERACTIONS
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTROMAGNETIC INTERACTIONS
ELECTRONIC STRUCTURE
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
INTERACTIONS
LANTHANUM COMPOUNDS
LANTHANUM OXIDES
LEPTONS
LIFETIME
MOLECULAR ORBITAL METHOD
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
POSITRONS
RARE EARTH COMPOUNDS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
WAVE FUNCTIONS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES