Study of magnetoresistance under hydrostatic pressure in the deuterated organic superconductor d8-κ-(BEDT-TTF)2Cu(SCN)2

The Fermi surface topology of the deuterated organic superconductor d8-κ-(BEDT-TTF)2Cu(SCN)2 has been investigated by Shubnikov–de-Haas measurements under hydrostatic pressure (P<1.5 GPa), in high magnetic fields (B<17 T) and at low temperatures (T>900 mK). The pressure dependences of the α-orbit, as well as the effective mass, m∗, are resolved and correlated with the suppression of the superconductivity transition temperature, Tc, with increasing pressure. Superconductivity in d8-κ-(BEDT-TTF)2Cu(SCN)2 appears to be fully suppressed at pressures exceeding 0.25 GPa. The gap between the quasi-one-dimensional and quasi-two-dimensional section of the Fermi surface is seen to decrease with pressure. This gap, indicated by the magnetic breakdown field, is smaller in the deuterated than in the protonated sample.