A study of KCL lattice defects by thermoluminescence experiments

Abstract

Summary. --The thermoluminescent emission of X-irradiated potassium chloride is recorded simultaneously vs. temperature and wavelength. Samples of different origin and prepared through different processes, including thermal treatments, are examined. Most records show essentially two glow peaks, the wavelength of the one at higher temperature being slightly shifted toward the red. On the whole, experimental results suggest that luminescent centres are originated by potassium ion vacancies lying at a variable distance from interstitial potassium ions. The observed red shift is ascribed to the Coulomb energy of the pairs of these point defects of opposite charges. PACS 78.60.Kn -Thermoluminescence. PACS 61.70.Ey -Defects in crystals.

A study of lattice defects in alkali fluorides by thermoluminescence experiments

“…Indeed, CaF2 showed emissions at 459 and 607 nm attributable to recombinations of conduction band electrons with holes bound in H centres and VF centres, respectively [5]. Likewise, the presence of recombination levels attributable to H and VF centres was observed in the TL emission of NaC1 [6] and KC1 [7]. In our opinion, this state of affairs substantiates the reliability of results obtained by TL investigation.…”

Investigating NaCl lattice defects by thermoluminescence

“…It is worthwhile noting that the role of interstitial Na + ions appears quite different with respect to K + ions in KC1. In fact, previous experiments on KC1 emission evidentiated that in this material tight pairs of interstitial-vacant K + ions, acting as bipolar recombination centres, are present [4]. This feature is not found in NaC1, perhaps because the small Na § radius (0.95/~ as compared with 1.33/~ for K +) allows an easy diffusion of Na + interstitials, thus breaking the pairs.…”