Glass Physics and Chemistry 

About: Glass Physics and Chemistry is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Crystallization & Glass transition. It has an ISSN identifier of 1087-6596. Over the lifetime, 2333 publications have been published receiving 13077 citations. The journal is also known as: Fizika i himiâ stekla.

Models of Disorder

Abstract: The stochastic matrix method is used to describe the statistical processes that take place when a glass is formed. We stress the physical features of the model and the relevancy of the hypotheses made. The theory is applied to various types of binary and ternary chalcogenide glasses, and the predictions of the model are compared with the experimental data. We also reveal the influence of doping on the transition temperature. The theory is extended to the case of growing a disordered solid on a substrate.

Problems of compatibility of the values of glass transition temperatures published in the world literature

Abstract: The influence of different factors (primarily, the temperature-time conditions for preparation and measurement of samples) on the glass transition temperatures determined from the temperature dependences of properties is analyzed using the calculations performed in terms of the relaxation theory of glass transition. The most optimum conditions for measurement of the glass transition temperatures T g that ensure the compatibility of the values of T g obtained by different researchers are recommended. The validity of the assertion that the glass transition temperature T g is a temperature at which the viscosity of glasses is equal to 1013 P is considered.

Shielding efficiency of lead borate and nickel borate glasses for gamma rays and neutrons

Abstract: Gamma ray exposure buildup factor (EBF) and neutron shielding efficiency of borate glass systems in composition (100 − x − y) Na2B4O7−xPbO−yNiO (where x and y = 0, 2, 4, 6, 8 and 10 weight percentage) were investigated in the present study. Gamma ray EBF values were computed using Geometric Progression (G-P) method for photon energy 0.015 to 15 MeV up to penetration depths of 40 mfp (mean free path). The macroscopic effective removal cross-sections (Σ R ) for fast neutron (2 to 12 MeV) were calculated. At low- and high-energy region, the EBF values were found minimum whereas maximum in the intermediate-energy regions with a sharp peak below 100 keV for oxide containing glass samples. The investigation was carried out for potential applications of borate glasses for radiation shielding.

Software for determining the thermal expansion tensor and the graphic representation of its characteristic surface (theta to tensor-TTT)

Abstract: A software is developed for determining the parameters of the thermal expansion tensor of the crystals of any system by a set of experimental diffraction data received using X-ray, synchrotron and other radiations at various temperatures. An algorithm is realized which allows carrying out all calculations from the experimental determination of the Bragg reflection angles to the calculation of the parameters of the thermal expansion tensor of the crystals, including the orientation of the tensor axes with respect to the crystallographic axes. The drawing of the 3D characteristic surface of the tensor and its 2D sections is also provided. The software is aimed at studying the anisotropy of the thermal expansion of the crystal materials and phase transitions, as well as revealing the mechanism and nature of the thermal behavior of substances.

Oxide crystals for electro-optic Q -switching of lasers

Abstract: A new generation of oxide crystals is emerging for electro-optic Q-switching or control of high-power pulsed lasers. Unlike the acousto-optic Q-switches in which the total turn-off time is limited by the duration of sound wave propagation (110–220 ns/mm) across the beam diameter, the electro-optic devices provide a short (<10 ns) response needed for minimum losses. Extinction ratios of better than 100 : 1 for electro-optic crystals ensure their reliable hold-off. By contrast, acousto-optic devices are characterized by single-pass dynamic losses of approximately 40%, which hinders their use in high-gain lasers. The basic principles of electro-optic Pockels cells are discussed. The performance characteristics of Q-switching for traditional electro-optic materials [deuterated potassium dihydrogen phosphate (DKDP), lithium niobate (LNB)] and other new electro-optic crystals, such as barium metaborate (BBO) and crystals belonging to the langasite (LGS) and potassium titanyl phosphate (KTP) families, are reviewed comparatively. Particular emphasis is placed on KTP-type electro-optic crystals, primarily on rubidium titanyl phosphate RbTiOPO4 (RTP), which stand out in their ability to provide Q-switching at extremely high frequencies or repetition rates up to 200 kHz. The use of both X- and Y-oriented double crystals as Q-switches in order to combine large electro-optic coefficients and low quarter-wave hold-off voltages with excellent thermal stability of the device is considered.