Polycrystalline techniques for conductivity studies of organic charge transfer salts

Polycrystalline compaction conductivity measurements are extensively used to characterize newly synthesized quasi-one-dimensional organic charge transfer salts. This technique, however, can be both quantitatively and qualitatively misleading. Studies of the polycrystalline compaction and single crystal conductivities of a variety of tetracyanoquinodimethan (TCNQ) salts allow us to define the limits of reliability of the polycrystalline compaction technique, and denote its shortcomings. A new polycrystalline technique, the voltage shorted compaction (VSC), is described. The VSC has proven to be a valuable aid in characterizing the electrical properties of new materials where single crystals are difficult to produce.