Role of bonding, reduced screening, and structure in the high-temperature superconductors

Journal Article · Wed Dec 01 00:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.16690· OSTI ID:5722750

Falter, C; Klenner, M; Chen, Q ^[1]

---

1. Institut fuer Theoretische Physik II, Festkoerperphysik, University Muenster, Wilhelm Klemm Strasse 10, 48149 Muenster (Germany)

In this paper we have studied the role of bonding, reduced screening, and structure in high-temperature superconductors (HTSC) using La[sub 2]CuO[sub 4] as a prototype material. In addition to the ionic and metallic component of bonding recently investigated, we estimate the influence of covalence effects on the structural parameters and the phonon spectrum. Also, the effect of a reduced dispersion of the electronic band structure on the polarizability and the phonon frequencies is considered and (hypothetical) mechanisms are investigated, which would favor ferroelectricity in the HTSC. In a further topic we deal with reduced screening, introduced by nonadiabatic effects related to the quasi-two-dimensional band structure and its consequence for the electron-phonon interaction, the phonon dispersion, and the pairing mechanism. We then focus our interest on features related to the tetragonal-to-orthorhombic phase transition in La[sub 2]CuO[sub 4]. Structural parameters are calculated and the influence of the transition on the phonon dispersion as well as on the phonon-induced charge fluctuations is discussed. Finally, we present, on the basis of nonlocal electron-phonon interaction of the charge-fluctuation type, a theoretical interpretation of a universal relationship between [ital T][sub [ital c]] and the hole content in the HTSC.

• OSTI ID: 5722750
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 48:22; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
HIGH-TC SUPERCONDUCTORS
BONDING
COPPER OXIDES
CRITICAL TEMPERATURE
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRON-PHONON COUPLING
LANTHANUM OXIDES
SCREENING
CHALCOGENIDES
COPPER COMPOUNDS
COUPLING
FABRICATION
JOINING
LANTHANUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SUPERCONDUCTORS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
665411* - Basic Superconductivity Studies- (1992-)