Recovery of the metallic state and quantum oscillations in a dielectric salt of the (ET)8[Hg4X12(C6H5Y)2] family at X = Y = Br under compression

Abstract

The quasi-two-dimensional organic conductor (ET)8[Hg4Br12(C6H5Br)2] (ET is bis(ethylenedithio)tetrathiafulvalene) undergoes a metal-insulator phase transition at T ∼ 170 K. It has been shown that a pressure of 8 kbar suppresses this transition and holds a metallic state to liquid-helium temperatures. Shubnikov—de Haas quantum oscillations with the single frequency F = 215 T have been observed in a magnetic field up to 15 T. The properties of this salt are compared to the properties of the (ET)8[Hg4Cl12(C6H5Cl)2] salt of the same family. Time annealing provides an important effect on the conducting properties of the salt under investigation.