Effects of neutron irradiation induced defects and chemical impurities on the 'DC' conductivity of TTT2I3

Abstract
The roles of disorder and impurities are studied in the highly conducting organic charge transfer salt TTT2I3. It is shown that impurities in the conducting TTT chains change the conductivity much more than an enhanced disorder in the iodine chains. In situ low-temperature neutron irradiation measurements indicated that molecular concentrations of defects of the order 10-3 increase the low-temperature (21K) resistivity by a factor of three and increase the temperature of the conductivity maximum by more than 100K. Measurements on crystals containing different amounts of chemical impurities and on TTTI1.5-xBrx alloys confirmed this picture.