J. Phys. I France
Volume 3, Numéro 12, December 1993
Page(s) 2411 - 2416
DOI: 10.1051/jp1:1993253
J. Phys. I France 3 (1993) 2411-2416

New organic superconductor based on deuterated bis(ethylenedithio)-tetrathiafulvalene, $\kappa$-(d 8-ET) 4(HgBr 2 $\cdot$ Hg 2Br 6)

R. B. Lyubovskii, R. N. Lyubovskaya, O. A. Dyachenko, V. V. Gritsenko, M. K. Makova and V. A. Merzhanov

Institute of Chemical Physics in Chernogolovka, Russian Academy of Sciences, Chernogolovka MD, 142432 Russia

(Received 22 January 1993, revised 27 July 1993, accepted 23 August 1993)

The deuterated organic salt based on (d 8-ET) (ET is bis(ethylenedithio) tetrathiafulvalene (BEDT-TTF)) was synthesized with bromine-mercurate anion. X-ray crystallographic studies have demonstrated it to have the following formula, $\kappa$-(d 8-ET) 4 (HgBr 2 $\cdot$ Hg 2Br 6). Various types of the temperature dependences of conductivity for the crystals from the same batch have been found but not one of the studied samples was a superconductor at ambient pressure. All crystals studied at ambient pressure seem to become superconductors at low pressure (~300 bar) with different $T_{\rm c}$. Crystal structure features of this salt with d 8-ET cation are compared with the structure of an organic superconductor (ET) 4Hg 2.89Br 8 at ambient pressure. The differences in their superconducting properties are associated with high lability of Hg-containing salts.

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