Superconductivity of {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br: Isotope effect revisited[bis(ethylenedithio)tetrathiafulvalene]

Conference · Wed Jul 01 04:00:00 EDT 1998

OSTI ID:20034172

Tokumoto, M; Kinoshita, N; Tanaka, Y; Anzai, H

In 1991, the authors reported a normal isotope effect in organic superconductor {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br, when all the hydrogen atoms of BEDT-TTF were replaced with deuterium. In other words, T{sub c} was depressed by as much as 0.9 K, in contrast to the inverse isotope effect commonly observed in 10K-class organic superconductors. Recently, it was reported that the deuterated {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br shows an insulating nature when cooled very rapidly. Therefore, it is necessary for us to reexamine the superconducting transition of both deuterated and undeuterated {kappa}-(BEDT-TTF){sub 2}Cu[N(CN){sub 2}]Br by SQUID measurements with special attention to the cooling speed. The authors studied the effect of cooling rate ranging from 10K/min down to as slow as 0.02 K/min, and observed a significant effect not only on the superconducting transition temperature T{sub c} but also on the superconducting volume fraction.

• Research Organization: Electrotechnical Lab., Tsukuba, Ibaraki (JP)
• OSTI ID: 20034172
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BEDT-TTF
BROMIDES
COOLING
COPPER COMPOUNDS
CYANIDES
DEUTERIUM
EXPERIMENTAL DATA
ISOTOPE EFFECTS
SUPERCONDUCTIVITY
TRANSITION TEMPERATURE