Crystal Structures, and Electrical Conducting and Magnetic Properties in the Plate Crystals of (Ethylenedithiotetrathiafulvalenoquinone-1,3-dithiolemethide)2·MX4 (M=Fe, Ga, X=Br; M=Fe, X=C1) Salts

We present recent results on the characterization of highly ordered polycrystalline thin films of the charge transfer salt TTF-TCNQ (TTF=tetrathiafulvalene, TCNQ=tetracyanoquinodimethane) prepared by thermal sublimation in high vacuum under different conditions. The increase in orientation and microcrystal size as a function of substrate and annealing temperatures is addressed. A consequence of such an increase is the reduction of the conductivity activation energy, which eventually leads to the observation of the Peierls transition by resistivity measurements. X-ray absorption near edge spectroscopy studies performed with synchrotron radiation reveal directly the influence of charge transfer on unoccupied states near the Fermi level.