Resonance Raman investigations of the symmetric stretching mode of I/sub 3/ /sup -/ anions in. cap alpha. and. beta. phases of di-bis(ethylenedithio)tetrathiafulvalene tri-iodide
Journal Article
·
· Phys. Rev. B: Condens. Matter; (United States)
OSTI ID:5573133
The resonance Raman spectra of I/sub 3/ /sup -/ anions in the organic superconductor ..beta..-(BEDT-TTF)/sub 2/I/sub 3/ (BEDT-TTF represents bis(ethylenedithio)tetrathiafulvalene) were studied and discussed in comparison with the nonsuperconducting phase of ..cap alpha..-(BEDT-TTF)/sub 2/I/sub 3/. In both modifications at low temperature a splitting of the Raman mode assigned to the symmetric stretching mode of the I/sub 3/ /sup -/ anions was discovered. The splitting of this mode in the ..beta..-(BEDT-TTF)/sub 2/I/sub 3/ crystals is related to the commensurate superstructure developed below 125 K in contradiction to the ..cap alpha.. phase where the splitting is related to a crystal-field effect. It is shown that an electronic excitation of the ..beta..-phase crystals by laser light can induce a structural transformation at least in a thin layer of the surface. This transformation is observed by a disappearance of the splitting of the symmetric stretching mode. The structural change can be related to a transformation from the commensurate superstructure with a superconducting transition temperature T/sub c/ = 1.3 K into a more ordered and symmetric structure which becomes superconducting at T/sub c/ = 8.1 K.
- Research Organization:
- Max-Planck-Institut fuer Medizinische Forschung, Abteilung fuer Molekulare Physik, Jahnstrasse 29, 6900 Heidelberg, West Germany
- OSTI ID:
- 5573133
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 36:13; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
Similar Records
ESR study of two phases of di(bis(ethylenedithio)tetrathiafulvalene)triiodide ((BEDT-TTF)/sub 2/I/sub 3/)
Effects of anion size and disorder on spin resonance in the BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) salts
Neutron and x-ray diffraction evidence for a structural phase transition in the sulfur-based ambient-pressure organic superconductor bis(ethylenedithio)tetrathiafulvalene triiodide
Journal Article
·
Sun Sep 01 00:00:00 EDT 1985
· Phys. Rev. B: Condens. Matter; (United States)
·
OSTI ID:5453931
Effects of anion size and disorder on spin resonance in the BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) salts
Conference
·
Thu Dec 31 23:00:00 EST 1987
·
OSTI ID:7144765
Neutron and x-ray diffraction evidence for a structural phase transition in the sulfur-based ambient-pressure organic superconductor bis(ethylenedithio)tetrathiafulvalene triiodide
Journal Article
·
Fri Nov 30 23:00:00 EST 1984
· Phys. Rev. B: Condens. Matter; (United States)
·
OSTI ID:6243482
Related Subjects
36 MATERIALS SCIENCE
360603* -- Materials-- Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
BEDT-TTF
CHARGED PARTICLES
CRYSTAL FIELD
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FUNCTIONS
HETEROCYCLIC COMPOUNDS
IONS
LATTICE VIBRATIONS
MOLECULAR STRUCTURE
ORDER-DISORDER TRANSFORMATIONS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RAMAN SPECTRA
RESONANCE
RESPONSE FUNCTIONS
SPECTRA
SUPERCONDUCTIVITY
360603* -- Materials-- Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANIONS
BEDT-TTF
CHARGED PARTICLES
CRYSTAL FIELD
CRYSTAL-PHASE TRANSFORMATIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FUNCTIONS
HETEROCYCLIC COMPOUNDS
IONS
LATTICE VIBRATIONS
MOLECULAR STRUCTURE
ORDER-DISORDER TRANSFORMATIONS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RAMAN SPECTRA
RESONANCE
RESPONSE FUNCTIONS
SPECTRA
SUPERCONDUCTIVITY