Physical properties of a molecular conductor (BEDT-TTF)₂I₃nanohybridized with silicananoparticles by dry grinding

Abstract

The dry grinding of a mixture of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) and silica nanoparticles has produced powdery (BEDT-TTF)-silica nanocomposites. The (BEDT-TTF)-silica nanocomposites are readily doped with iodine in hexane dispersion to give powdery nanocomposites of (BEDT-TTF) 2 I 3 -silica. XRD and TEM measurements suggest that (BEDT-TTF) 2 I 3 in the nanocomposite exists as shell layers of core-shell-type nanoparticles and as nanometer-sized crystals incorporated into hollow sites of aggregated silica nanoparticles. Magnetic susceptibility measurements reveal that the nanocomposites accompanied a large number of Curie spins attributable to surface molecules of the core-shell-type nanoparticles. The nanocomposites show a magnetic susceptibility change corresponding to the metal-insulator transition of α-(BEDT-TTF) 2 I 3 in a broad temperature range of 110-140 K, which is attributed to the properties of the nanocrystalline components. Doping in diethyl ether dispersion leads to higher amounts of the nanocrystalline component being obtained. The doping of Page 3 of 20 RSC Advances 2(BEDT-TTF)-silica nanocomposites by dry grinding produces a paramagnetic powder containing amorphous (BEDT-TTF) 2 I 3 , which possesses a Curie spin concentration of 50%. The effects of annealing on these nanocomposites are investigated. The electrical conductivity of the compaction pellets of (BEDT-TTF)-silica nanocomposites is enhanced by iodine doping to reach approximately 10 −6 S•cm −1 , but the value is much lower than that of the bulk crystals (10 1 S•cm −1 ).

Four Molecular Superconductors Isolated as Nanoparticles

“…[13] Core-shell highly dispersed NPs that consist of the molecular conductor as the core material and the stabilizing agent as the shell layer can be isolated by using appropriate stabilizing agents. Polyvinylpyrrolidone (PVP) (Scheme 3) was successfully used to prepare NPs of (BEDT-TTF) 2 I 3 .…”

Nanoparticles of molecule-based conductors

“…24 An interesting approach to produce (BEDT-TTF) 2 I 3 at a nanometric size used silica NPs as the surface of growth. 25 The composite contains core-shell-type NPs; nanometre-sized crystals of (BEDT-TTF) 2 I 3 act as shell layers and as the binder in aggregated silica particles. Silica polymeric gel is indeed an interesting medium for imbedding NPs.…”

Preparation of environmentally resistant conductive silica-based polymer hybrids containing tetrathiafulvalene–tetracyanoquinodimethane charge-transfer complexes

“…34 By conjugation to silica, the formation of highly ordered structures has been demonstrated. [36][37][38][39][40] Despite the usability and versatility of TTF polymer composites, there is considerable room to increase the environmental resistance of TTF polymer composites. For example, as shown in our previous work, the conductivity of these composites decreases after heating at temperatures of 480 1C for several minutes.…”