Superconducting properties and Fermi-surface topology of the quasi-two-dimensional organic superconductor lambda-(BETS)(2)GaCl4 (BETS bis(ethylene-dithio)tetraselenafulvalene)

Citation
C. Mielke et al., Superconducting properties and Fermi-surface topology of the quasi-two-dimensional organic superconductor lambda-(BETS)(2)GaCl4 (BETS bis(ethylene-dithio)tetraselenafulvalene), J PHYS-COND, 13(36), 2001, pp. 8325-8345
Citations number
83
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHYSICS-CONDENSED MATTER
ISSN journal
09538984 → ACNP
Volume
13
Issue
36
Year of publication
2001
Pages
8325 - 8345
Database
ISI
SICI code
0953-8984(20010910)13:36<8325:SPAFTO>2.0.ZU;2-B
Abstract
The Fermi-surface topology of the organic superconductor lambda-(BETS)(2)Ga Cl4 has been determined using the Shubnikov-de Haas and magnetic breakdown effects and angle-dependent magnetoresistance oscillations. The former expe riments were carried out in pulsed fields of up to 60 T, whereas the latter employed quasistatic fields of up to 30 T. All of these data show that the Fermi-surface topology of lambda-(BETS)(2)GaCl4 is very similar to that of he most heavily studied organic superconductor, kappa-(BEDT-TTF)(2)Cu(NCS) (2), (BEDT-TTF drop bis(ethylene-dithio)tetrathiafulvalene), except in one important respect: the interplane transfer integral of lambda-(BETS)(2)GaCl 4 is a factor similar to5 larger than that of kappa-(BEDT-TTF)(2)Cu(NCS)(2) . The increased three-dime,nsionality of k-(BETS)(2)GaCl4 is manifested in radio-frequency penetration-depth measurements, which show a clear dimensio nal crossover in the behaviour of H-c2(T). The radio-frequency measurements have also been used to extract the Labusch parameter determining the fluxo id interactions as a function of temperature, and to map the flux-lattice m elting curve.