ABSTRACT
ITC-spectra of NaCl and KCl crystals doped with Eu++, Pb++ and Ni++ were studied in a T-range of 120 and 400 K. These spectra exhibit, among others, the presence of ahuge band positioned well above RT. Systematic studies showed that the position of the band maximum and its amplitude are extremely sensitive to any changes of the crystal structure. Macro-scopically, the Maxwell /Wagner/ Sillars model of heterogenous dielectrics explains the behaviour of this band. Microscopically, the dislocation lines, surrounded either by a Cottrell like atmosphere or by precipitate-occlusions could play the electrical properties of which differ from those of the matrix.
