Charge transport and polarization in effectively insulated and in contacted NaCl crystals below 500 K

Abstract

An attempt is made to establish and to verify from thermally stimulated current, dc conductivity, ac impedance, and other data and from their interpretation by means of the concept of a surface polarization by point defects (derived from the generally accepted space‐charge formation theory) the true, i.e. the bulk conductivity, of NaCl at low temperatures and to estimate thus the limiting effect of electrodes on the charge transport through the crystals. Further the attempt is made to elucidate the character of the “polarization process” connected with the passage of the current.

Study of effect of quenching and deformation on KCl: Gd3+ crystals by using conductivity measurements

“…During last few decades, considerable attention has been devoted to study the nature of lattice defects in alkali halide crystals doped with divalent cations (Alnatt et al 1972;Nadler and Rossel 1973;Kessler 1992;Saibabu 1995) and to a much lesser extent with divalent anions (Saibabu et al 1991(Saibabu et al , 2002Saibabu 1998). On the other hand, there is very little data available on trivalent cations doped in alkali halides (Prizbram 1975;Beniere and Rokbani 1977).…”

“…Ionic conductivity as a function of temperature has been measured (Saibabu et al 1991(Saibabu et al , 2002Kessler 1992;Saibabu 1995Saibabu , 1998 on alkali halide crystals doped with divalent cations as well as anion impurities. The effect of quenchinduced changes on conductivity of doped crystals has been investigated by a number of workers (Buniya 1977;Saibabu et al 1991Saibabu et al , 2002Saibabu 1995Saibabu , 1998.…”