Abstract
The organic superconductor κ-(BEDT-TTF)2Cu(SCN)2 has been investigated at room temperature by polarized mid-infrared (600-7000 cm-1) reflectivity measurements at pressures of up to 1.7 GPa. The optical effective mass, mopt, decreases linearly with pressure, in contrast to the pressure dependence of the effective mass, m*, determined by magnetic quantum oscillation measurements (Caulfield J et al 1994 J. Phys.:Condens. Matter 6 2911-24; Caulfield J et al 1995 Synth. Met. 70 815-8). Most phonon modes are seen to exhibit a linear pressure dependence of 0.5-1%/GPa. The stronger pressure dependence of the central C=C mode of the BEDT-TTF molecule is discussed: it is thought to be due to the pressure dependence of the effective Coulomb repulsion in κ-(BEDT-TTF)2Cu(SCN)2. These measurements suggest that a change in the electron-electron interaction under pressure could be the relevant factor for the suppression of superconductivity under pressure in κ-(BEDT-TTF)2Cu(SCN)2.
Original language | English |
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Pages (from-to) | L247-L256 |
Journal | Journal of Physics Condensed Matter |
Volume | 12 |
Issue number | 13 |
DOIs | |
Publication status | Published - 2000 Apr 3 |
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics