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Structure sensitivity of relaxation phenomena in NaCl and KCl crystals doped with some divalent impurities [I] ITC‐spectra characteristic of the as‐cleaved state

1984; Wiley; Volume: 19; Issue: 10 Linguagem: Inglês

10.1002/crat.2170191025

1521-4079

M. Suszyńska, R. Capelletti,

Advanced Scientific and Engineering Studies

Abstract ITC spectra of NaCl and KCl crystals doped with europium, lead, and nickel (in a wide concentration range) have been measured at temperatures between 120 and 400 K. It has been shown that the spectra taken for as cleaved samples are usually very rich. The origin and behaviour of the high‐temperature peaks (above the IV‐dipole peak) have been discussed in frames of the S ILLARS theory of Maxwell/Wagner‐type polarization effects in heterogeneous dielectrics. It is suggested that the peak positioned near room temperature is related with any type of vacancy rich precipitates formed within otherwise homogeneous crystal lattice. The second peak, positioned at still higher temperatures, is a Maxwell/Wagner effect due to dislocations surrounded by impurity‐related imperfections in a fashion of the so called Cottrell atmosphere.