[en] Published in summary fomr only

[en] We present atomic resolution images of monatomic step edges on the KBr(001) surface imaged by dynamic force microscopy operated in the non-contact mode. Under certain experimental conditions, we observe a systematic and reversible change of the atomic contrast when the tip crosses the step. This change is attributed to the reversal of the polarity of the ionic tip under the influence of the tip-substrate interaction in the immediate vicinity of the step edge. This polarity reversal is attributed to a change in the atomic structure of the tip and is described by a transition between the two potential wells of a two-level system localized near the tip apex. The case of two monatomic steps imaged in succession is also investigated in detail. The results indicate that the two-level system associated with the reversal of the tip polarity involves the movement of a very limited number of ions on the tip

[en] We present a study of the electronic excitations in insulating materials using an embedded- cluster method. The excited states of the embedded cluster are studied systematically using time-dependent density functional theory (TDDFT) and high-level equation-of-motion coupled cluster (EOMCC) methods. In particular, we have used EOMCC models with singles and doubles (EOMCCSD) and two approaches which account for the effect of triply excited configurations in non-iterative and iterative fashions. We present calculations of the lowest surface excitations of the well-studied potassium bromide (KBr) system and compare our results with experiment. The bulk-surface exciton shift is also calculated at the TDDFT level and compared with experiment

[en] Processes of localization and migration of K_i⁺Br_i^- interstitial dipole in KBr lattice were carried out by the computerized stimulation. Simulation was conducted by the MNDO quantum-chemical method. Clusters consist from 216 ions with accounting of relaxation of 114 ions of the defects surroundings. The computer calculation shows, that the K_i⁺Br_i^- dipole is localizing in the crystal lattice due to formation of chemical bond with ions of the neighboring surroundings. In this time the dipole can exists in two forms

No abstract available

[en] We report the generation of a beam of slow (translationally cold) KBr molecules formed by exoergic reactive collisions in counterpropagating beams of K atoms and HBr molecules. The intensity of the slow beam is estimated to 4x10¹¹ s^-1 sr^-1. The velocity distribution (density) peaks at 42.5 m/s corresponding to a formal temperature of 13 K. About 7% of the molecules move at velocities between 14.2 and 20 m/s and an estimated fraction of 7% is slower than 14.2 m/s

[en] Dislocation loops of interstitial and vacancy types were observed to form in kBr foils during examinations in 100 kV transmission electron microscope. The examinations were carried out in the temperature range between +20 and -110⁰C. Small crystallites were also observed to grow on a surface of foils, when the foils were heavily irradiated at -110⁰C with electrons

[en] Most creep experiments on alkali halides have used single crystal specimens, and only relatively little information is available on the creep characteristics of polycrystalline materials (primarily LiF and NaCl). In addition, there is the possibility of marked differences in impurity content between the single and polycrystalline samples, which make it difficult to compare the limited data at present available. Accordingly, this paper describes a series of experiments conducted on KBr with the objective of overcoming these difficulties. The specific aims of this work were threefold. First, to conduct creep tests on KBr single crystals in <100> orientation. Second, to prepare polycrystalline samples of KBr from the same source of single crystals. Third, to conduct creep tests on the polycrystalline material for a direct comparison with the single crystal data

[en] A fiber-optic dosimetry system using optically stimulated luminescence (OSL) of KBr:Eu was developed and its utility in near-real-time dosimetry has been tested under various medical radiation fields. The OSL response was observed to exhibit component-specific sensitivity changes while operating in the high-dose-rate regions of proton and gamma fields. The present paper provides a more detailed look at the relationship between thermoluminescence (TL) and OSL of KBr:Eu, and proposes a model to describe the mechanisms responsible for the sensitivity change

[en] In this article, a fractal concept is used to evaluate the morphological features of KBr layers, deposited in a controlled vacuum environment. To the best of our knowledge, for the first time, self-affine or self similar nature of KBr film surfaces was examined by autocorrelation function. Theoretical estimations revealed that irregularity/complexity of growing KBr layers was significantly influenced by the thickness. The global interface width and lateral correlation length were monotonically decreased with increasing film thickness. On the contrary, fractal dimension and local roughness exponent, estimated by height-height correlation function, did not suggest such dependency. (paper)