Einfluß der thermischen Behandlung auf die Ionenleitfähigkeit von KCl im Störleitungshereich

Abstract

The ionic conductivity of Harshaw KCl-crystals has been measured in the extrinsic range using adc-method. For the steady state currentOhm's law was obeyed up to 2000 V cm⁻¹. The influence of the heating- and cooling-rates on the conductivity was extensively studied. It was concluded from the results that in the range 160–250 °C the carrier concentration changed with temperature according to a very slow, reversible process, which is tentatively interpreted as precipitation of impurities. If the same values for the conductivity at a given temperature were to be obtained in the heating stage as in the cooling stage, the sample had to be passed through this temperature range very slowly. The precipitation could be frozen in by rapid cooling from 250 °C. In this quenched state the increased conductivity was accompanied by an increased polarization.