J. Phys. II France
Volume 1, Numéro 9, September 1991
Page(s) 1015 - 1019
DOI: 10.1051/jp2:1991202
J. Phys. II France 1 (1991) 1015-1019

Competition between insulating and superconducting states in $\kappa$-(BEDT-TTF) 2CuN(CN) 2Cl: pressure effect

Yu. V. Sushko1, V.A. Bondarenko1, R.A. Petrosov1, N.D. Kushch2 and E.B. Yagubskii2

1  Institute of Semiconductors, Ukrainian Academy of Sciences, Kiev 252650, Ukraine, U.S.S.R.
2  Institute of Chemical Physics, Academy of Sciences of the USSR, Chernogolovka, 142432, U.S.S.R.

(Received 21 May 1991, accepted in final form 19 June 1991)

The pressure effect on the resistance behavior of the organic superconductor $\kappa$-(BEDT-TTF) 2CuN(CN) 2Cl is studied. At ambient pressure it has an insulating ground state, however at a modest pressure of 150 bar superconductivity with $T_{\rm c}$ near 12 K appears and coexists with high-temperature semiconducting regime in pressure range up to 340 bar, where the later is fully suppressed and superconducting transition temperature reaches the maximum value (midpoint 12.7 K, onset 13.4 K). Under further pressure increasing $T_{\rm c}$ strongly decreases. The details of the resistance behavior at different pressures and the relation between superconducting and insulating states are discussed.

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