Photoinduced self-localized structural distortions in YBa/sub 2/cu/sub 3/O/sub 7/-delta: direct evidence of polarons or bipolarons. Technical memo

Technical Report · Sun May 01 00:00:00 EDT 1988

OSTI ID:6743903

Kim, Y H; Foster, C F; Heeger, A J; Cox, S; Stucky, G

Photoinduced infrared absorption measurements of YBa/sub 2/Cu/sub 3/O/sub 7/-delta (delta=0.75) in the spectral region from 150/cm to 4000 cm are reported. We observed photoinduced infrared active vibrations (IRAV) modes, associated phonon bleachings, and an electronic transition (from a localized gap state) peaked at 1050/cm (0.13 eV). The spectral features indicate a local tetragonal to orthorhombic distortion in the Cu-O plane around the photoinduced charge carriers in YBa/sub 2/Cu/sub 3/O/sub 7/-delta is smaller than La/sub 2/CuO/sub 4/. The photoinduced structural distortion and the associated self-localized gap state demonstrate that the photoexcitations are relatively long lived polarons or bipolarons.

• Research Organization: California Univ., Santa Barbara (USA). Dept. of Chemistry
• OSTI ID: 6743903
• Report Number(s): AD-A-196091/3/XAB; TR-5
• 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
CHALCOGENIDES
COPPER COMPOUNDS
COPPER OXIDES
CRYSTAL STRUCTURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHONONS
PHYSICAL PROPERTIES
POLARONS
QUASI PARTICLES
SPECTRA
SUPERCONDUCTIVITY
SUPERCONDUCTORS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES