Pressure effect on the magnetic susceptibility of low dimensional organic conductors α-, β-(BEDT-TTF)2I3 and (TMTSF)2X (X=ClO4, PF6, ReO4)

Abstract

The pressure dependence of the static susceptibility of the α and β phases of (BEDT-TTF)2I3 and of (TMTSF)2X for X = CI04, PF6, Re04 was measured using a Faraday balance up to a pressure of 10 kbar. The fractional pressure dependence σ InXs/σP is -2.0%/kbar and -3.3%/kbar for the α- and β-(BEDT-TTF)2I3 respectively and it is temperature independent. For (TMTSF)2X σ1nXs/σP is about -3.0%/kbar at room temperature and increases to -4.8%/kbar on cooling. Both the magnitude and temperature dependence of the fractional pressure dependence in those two families are in contrast with the behaviour in TTF-TCNQ, where the magnitude is -8.%kbar and decreases with decreasing temperature.