Published August 5, 1992 | Version v1
Journal article

13C double-bond 13C isotope effect for Tc and consequence regarding the superconducting pairing mechanism in κ-(ET)2X superconductors

Description

In this communication, the authors report the first determination of the isotope effect for 13C substitution in the central C double-bond C atoms of ET [ET is bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)] in the organic superconductors κ-(ET)2Cu[N(CN)2]Br (Tc = 11.6 ± 0.05 K, diamagnetic onset) and κ-(ET)2Cu(NCS)2 (Tc = 9.8 ± 0.3 K, diamagnetic onset). These materials, presently the highest-Tc electron-donor-based, ambient-pressure organic superconductors, are much better materials for tests of the isotope effect for ET-based superconductors than pressurized β-(ET)2I3 because Tc is easily reproducible from sample-to-sample at ambient pressure. These results show that the central C double-bond C stretching motion is not a dominant exchange mechanism over conventional BCS-type phonon exchange for superconducting pairing in κ-(ET)2Cu[Nu(CN)2]Br and κ-(ET)2Cu(NCS)2

Additional details

Publishing Information

Journal Title
Inorganic Chemistry
Journal Volume
31
Journal Issue
16
Journal Page Range
p. 3346-3348.
ISSN
0020-1669
CODEN
INOCAJ