Anomalous Behavior of the Thermoelectric Power in the Vicinity of the Superconducting Transition in the Organic Superconductors ?-(BEDT-TTF)2Cu(NCS)2 and ?-(BEDT-TTF)2Cu[ N(CN)2] Br

1996 ◽  
Vol 6 (12) ◽  
pp. 2051-2060 ◽  
Author(s):  
G. Yu. Logvenov ◽  
M. V. Kartsovnik ◽  
H. Ito ◽  
T. Ishiguro ◽  
M. Kund ◽  
...  
Keyword(s):  
Thermoelectric Power ◽  
Anomalous Behavior ◽  
Organic Superconductors ◽  
Superconducting Transition

scholarly journals Microscopic Observation of π Spin Polarization by d Localized Spin in λ Type BETS Based Organic Superconductors

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1055
Author(s):  
Ko-ichi Hiraki ◽  
Toshihiro Takahashi ◽  
Hiroshi Akiba ◽  
Yutaka Nishio ◽  
Biao Zhou
Keyword(s):  
Magnetic Field ◽  
Low Temperature ◽  
Spin Polarization ◽  
Organic Superconductors ◽  
Exchange Field ◽  
Superconducting Transition ◽  
Nmr Spectrum ◽  
Fe Sites ◽  
Low Magnetic Field ◽  
Ga Doping

In this study, 77Se NMR measurements were carried out to detect the π spin polarization of the organic BETS (BETS = Bis(ethylenedithio)tetraselenafulvalene) molecule of the field induced superconductor, λ-(BETS)2Fe1−xGaxCl4, which shows a superconducting transition at relatively low magnetic field compared to the non-doped λ-(BETS)2FeCl4. From the analysis of the NMR spectrum at low temperature, it was clarified that the exchange interaction between π and 3d spins in the Ga doping system is smaller than that in the Fe salt. It is also clarified that the conduction π spins feel the “averaged” exchange field from the localized 3d spins at the dilute Fe sites.

FERMI SURFACES OF ORGANIC SUPERCONDUCTORS

1993 ◽  
Vol 07 (15) ◽  
pp. 2707-2741 ◽  
Author(s):  
J. WOSNITZA
Keyword(s):  
Organic Superconductors ◽  
Spin Splitting ◽  
Quantum Limit ◽  
Superconducting Transition ◽  
Coupling Constant ◽  
Fermi Surfaces ◽  
Electron Phonon Coupling ◽  
Charge Transfer Salts ◽  
Almost All ◽  
Observable Spin

In this review an overview of the present-day knowledge of the Fermi surfaces of organic superconductors obtained by Shubnikov-de Haas (SdH) and de Haas-van Alphen (dHvA) experiments is given. Almost all measurements reported here were made on charge transfer salts of the type (ET)2X where ET stands for bis(ethelenedithio)-tetrathiafulvalene (or BEDT-TTF) and X is a monovalent anion. The ET-salts are characterized by their extremely two-dimensional properties. Some unique features resulting from this two-dimensionality, like gigantic SdH and dHvA oscillations, directly observable spin-splitting far from the quantum limit and a distinctive angular dependence of the dHvA amplitude will be discussed in detail. By comparison of the measured cyclotron effective mass with the bare band mass the electron-phonon coupling constant can be extracted and the validity of the BCS formula for the superconducting transition temperature can be checked.

Resistive superconducting transition of ?-type BEDT-TTF organic superconductors in a magnetic field

1994 ◽  
Vol 7 (3) ◽  
pp. 667-669 ◽  
Author(s):  
Hiroshi Ito ◽  
Takehiko Ishiguro ◽  
Tokutaro Komatsu ◽  
Nozomu Matsukawa ◽  
Gunzi Saito ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Organic Superconductors ◽  
Superconducting Transition

ANOMALOUS BEHAVIOR ABOVE Tc AND 90K SUPERCONDUCTIVITY IN YBa2Cu3Ox

1988 ◽  
Vol 02 (05) ◽  
pp. 737-742 ◽  
Author(s):  
CHENG XIAOHUA ◽  
SUN LINHAI ◽  
WANG YENING ◽  
SHEN HUIMIN ◽  
YU ZHENG
Keyword(s):  
Internal Friction ◽  
Lattice Parameter ◽  
Anomalous Behavior ◽  
Superconducting Transition ◽  
Internal Friction Peak ◽  
X Ray ◽  
Obvious Relation ◽  
Three Components

Internal friction and lattice parameter were measured by Marx’s three components oscillator and X-ray polycrystalline diffraction respectively. As a function of temperature, there exist a few anomalies above Tc, of which the 110K-130K anomaly is found to be closely connected with 90K superconducting transition, but no obvious relation was observed for the 210K anomaly. In addition, a relaxation type internal friction peak was measured at about 100K.

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