Biasing effects on thallium and silver chlorides with dc/ac voltage

Comparison was made between crystals of thallium chloride and silver chloride on their biasing effects with dc/ac voltage. Previous reports say that, although their electrical conductivities are similar, the dominant charge carriers in the former are the Cl− ions while the Ag+ ions in the latter. The present dc/ac study demonstrates the following: for thallium chloride, although Cl− conduction may be dominant under low bias field, Tl+ conduction supercedes Cl− conduction when the bias field is enhanced. For silver chloride, Ag+ conduction is overwhelming within wide temperature range, to cause easy dielectric breakdown on dc biasing. Concerning the extrinsic conductivity seen at temperatures below 60 °C (thallium chloride) or below 150 °C (silver chloride), it is ascribed to grain-boundary related electron conduction, not to grain-boundary related Tl+ or Ag+ conduction as reported earlier.