THERMAL STIMULATED CURRENT INVESTIGATION OF THE POLARIZATION OF NH4CL

Thermal stimulated currents of undoped, of NH3 and of NiCl2 doped crystals were measured and the obtained thermograms decomposed into individual first order kinetics and space charge peaks. Details concerning the procedure of decomposition are given. The results confirm the formation of anion and cation vacancies respectively in consequence of the doping and show that the charge transport is realized in several thermal stimulated steps. Below zero centigrade it is realized most probably by a sequence of proton transfers and restricted in distance. Above this temperature the vacancies become mobile and allow a steady d.c. current. The processes are explained by a 'catalytic' NH4+Cl-⇌NH3 + HCl reaction. © 1979 Springer-Verlag.