X-ray diffraction study and luminescence of agates of Southern Siberia

Central part of Kuznetsk Basin is known in the narrow circle of researchers as one of the regions of Siberia where agate mineralization is widespread. In spite of rather wide distribution of these quartz-chalcedony aggregates, still there are some unresolved issues about their origin. In this context it may be informative to use such methods as luminescence analysis and estimation of crystallinity indexes of minerals which constitute agates. Layer-by-layer X-ray diffraction study of minerals which make up distinct layers of agates and onyxes allowed identifying three minerals alternating: chalcedony, quartz and (less frequently) cristobalite. Calculation of crystallinity indexes of all of the layers with use of X-ray diffraction analysis helped to find changes of proportion between two states of silica – high-molecular (polymerized) and monomeric. X-ray luminescence analysis results confirmed this finding. Authors suppose that monomeric state is particularly related to high value of crystallinity index and presence of defects which are responsible for short-wavelength luminescence (280 nm)

X-ray induced and thermostimulated luminescence of new fluorine containing compounds (potential luminophores, scintillators and dosimeters)

X-ray induced luminescence spectra in optical range of wave-lengths (200–700 nm) and thermoluminescence curves for fluoride, fluorosulphate, fluorophosphate and fluorooxalate compounds of the titanium subgroup elements with alkali metals and ammonium have been obtained. Influence of annealing and repeated X-raying on luminescence (XRL) spectra of a number of compounds has been examined. Alloy additives influence on fluorine compounds XRL spectra has been examined. Most of compounds being under study may be used as X-ray luminophores, scintillators and dosimeters. The highest intensity of luminescence was achieved for such compounds as K2ZrF6, Cs2ZrF6, Rb2ZrF6 (especially for doped K2ZrF6), K2HfF6 and CsZr2(PO4)3. Radiation drifting to long-wave range for a number of fluorophosphatezirconates in comparison with fluorides may be a positive moment in making luminophores on their base