ELECTRICAL CONDUCTANCE IN ORGANIC SOLIDS

This report outlines progress made on a two-year program to study the electrical characteristics of some organic solids. The work is divided along three general lines: (1) the study of the transport of carriers injected into insulating (or poorly conducting) solids by an electron gun, (2) a series of electrical measurements on a highly conducting ion radical salt of tetracyanoquinodimethan, and (3) the study of carrier transport in some amorphous systems. A cryostated electron gun system has been designed, and construction is nearing completion. This device should enable us to make transport measurements in a variety of insulating materials between 4 and 300 K. Three techniques for determining the temperature coefficient of resistance of semi-metallic TCNQ salts have been investigated: (1) A. C. bridge methods for polycrystalline samples, (2) four-point-probe measurements on single crystals, and (3) microwave power loss in either polycrystalline or single crystal samples. Only the last appears promising, and further experiments with it are in progress. Sponsored in part by the DARPA.