Crystal Structures and Electrical Properties of BEDT-TTF Salts of Mercury(II) Thiocyanate with and without K Ion

Abstract

The electrochemical oxidation of BEDT-TTF with Hg(SCN)2, KSCN, and 18-crown-6 ether yielded two different BEDT-TTF salts of mercury(II) thiocyanate depending on the solvent used. The K+ containing salt, (BEDT-TTF)2[KHg(SCN)4], was metallic down to 1.5 K with various temperature dependences. The crystal structures showed an alternating stacking of two-dimensional networks of BEDT-TTF molecules and of KHg(SCN)4 anions. The other modification (BEDT-TTF)3[Hg(SCN)3] exhibited metal-insulator (MI) transition at around 180 K.

Experimental evidence for Fröhlich superconductivity in high magnetic fields

“…Resistivity and irreversible magnetisation data taken within the high magnetic field CDW x phase of the quasi-two-dimensional organic metal α-(BEDT-TTF) 2 KHg(SCN) 4 are shown to be consistent with a field-induced inhomogeneous superconducting phase. In-plane skin depth measurements show that the resistive transition on entering the CDW x phase is both isotropic and representative of the bulk.…”

“…Conduction by sliding CDWs due to their depinning may occur under large electric fields, but is accompanied by considerable dissipation [3]. In this respect, the organic conductor α-(BEDT-TTF) 2 KHg(SCN) 4 (together with the analogue compounds in which K has been substituted by Tl or Rb) may be an exception [4]. This highly anisotropic layered metal exhibits what is thought to be a CDW with an exceptionally low transition temperature T p ∼ 8 K [5,6,7,8,9].…”

“…This highly anisotropic layered metal exhibits what is thought to be a CDW with an exceptionally low transition temperature T p ∼ 8 K [5,6,7,8,9]. At applied magnetic fields (µ 0 H) greater than 23 T and temperatures (T ) less than 2 K, α-(BEDT-TTF) 2 KHg(SCN) 4 possesses a phase which carries dissipationless currents [10,11].…”

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

“…Saito, et al, 394,395 increase V cell considerably, and thus, are expected to increase V eff . The crystal structure of -(ET) 2 -MHg(SCN) 4 indicates that the 2D conducting layers are separated from each other by ca.…”

“…50). 394,395,398,399 Their calculated band structures consist of 1D and 2D Fermi surfaces as depicted in Figs. 30a and 30e.…”