Author/Authors :
Shimojo، نويسنده , , Y. and Kamiya، نويسنده , , S. and Tanatar، نويسنده , , M.A. and Ohmichi، نويسنده , , E. and Kovalev، نويسنده , , A.E. and Ishiguro، نويسنده , , T. and Yamochi، نويسنده , , H. and Saito، نويسنده , , G. and Yamada، نويسنده , , J. and Anzai، نويسنده , , H. and Kushch، نويسنده , , N.D. and Lyubovskii، نويسنده , , R.B. and Lyubovskaya، نويسنده , , R.N. and Yagubskii، نويسنده , , E.B.، نويسنده ,
Abstract :
The upper critical fields in the direction parallel to superconducting plane, Hc2″, of the layered salts κ-(BEDT-TTF)2X (X=Cu(NCS)2, Cu[N(CN)2]Br) and κ-(BEDT-TTF)4-Hg2.89Br8 far exceed the BCS Pauli paramagnetic limit and show variety of temperature (T) dependence at ambient pressure. We extended the studies of the Hc2″(T) diagrams for all main κ-(BEDT-TTF)2X superconductors by applying pressure. Emphasis is placed on the behaviour at low T and in high magnetic fields. The origin of the exceeding the BCS Pauli paramagnetic limit is discussed. The dependence of Hc2″ on the field direction within the plane is also presented.
Keywords :
Upper critical field , ?-(BEDT-TTF)2X , Pauli paramagnetic limit , order parameter
