Lattice dynamics of high- T sub c superconductors: Optical modes of the thallium-based compounds

Journal Article · Sat Mar 31 23:00:00 EST 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.41.6409· OSTI ID:7122760

Kulkarni, A D; de Wette, F W ^[1]; Prade, J; Schroeder, U ^[2]; Kress, W ^[3]

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1. Department of Physics, University of Texas, Austin, Texas 78712-1081 (USA)
2. Universitaet Regensburg, D-8400 Regensburg, Federal Republic of Germany (DE)
3. Max-Planck-Institut fuer Festkoerperforschung, Postfach 800665, D-7000 Stuttgart 80, Federal Republic of Germany (DE)

We present a lattice-dynamical calculation of the Raman- and infrared-active modes of the following six thallium-based high-{ital T}{sub {ital c}} superconductors: Tl{sub 2}Ba{sub 2}CuO{sub 6}, Tl{sub 2}CaBa{sub 2}Cu{sub 2}O{sub 8}, and Tl{sub 2}Ca{sub 2}Ba{sub 2}Cu{sub 3}O{sub 10} (body-centered-tetragonal structures) and TlCaBa{sub 2}Cu{sub 2}O{sub 7}, TlCa{sub 2}Ba{sub 2}Cu{sub 3}O{sub 9}, and TlCa{sub 3}Ba{sub 2}Cu{sub 4}O{sub 11} (simple-tetragonal structures). Our calculations are based on a shell model that incorporates short-range overlap potentials, long-range Coulomb potentials, and ionic polarizabilities. We also require that the shell models for different high-{ital T}{sub {ital c}} superconducting compounds be mutually compatible, namely that the short-range potentials for given ion pairs in equivalent environments be transferable from one compound to the other. The model presented here does in fact utilize a common set of short-range potentials that apply to the entire series of thallium-based superconductors as well as to YBa{sub 2}Cu{sub 3}O{sub 7} and Bi{sub 2}CaSr{sub 2}Cu{sub 2}O{sub 8}, studied earlier. The model reproduces the available experimental infrared and Raman data of all these compounds quite well and is thus supported by a broad database, albeit only of optical modes. We expect that our model, which is based on realistic interaction potentials, reproduces eigenvalues and eigenvectors to the same approximation. Thus we conclude from the satisfactory agreement between calculated and measured eigenfrequencies that the calculated eigenvectors provide a realistic description of the displacement patterns of the optical modes.

• OSTI ID: 7122760
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 41:10; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM OXIDES
BCC LATTICES
CALCIUM COMPOUNDS
CALCIUM OXIDES
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL LATTICES
CRYSTAL MODELS
CRYSTAL STRUCTURE
CUBIC LATTICES
EIGENFREQUENCY
EIGENVECTORS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
INFRARED SPECTRA
LATTICE VIBRATIONS
MATHEMATICAL MODELS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHYSICAL PROPERTIES
RAMAN SPECTRA
SPECTRA
SUPERCONDUCTIVITY
TETRAGONAL LATTICES
THALLIUM COMPOUNDS
THALLIUM OXIDES
THERMODYNAMIC PROPERTIES
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE