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1

Wpływ procesu redukcji na właściwości strukturalne i mechaniczne szkieł tlenkowych z grupy (Pb,Bi)-(Si,Ge)-O

Bochentyn B.

Technical Issues

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2015

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nr 2

3--8

EN

The effect of the reduction process in H2 at 380 °C on the microstructure and elemental composition of a glass Bi0.4Pb0.2Si0.4Ox has been investigated. It has been shown that after reduction a clearly separated top layer with a thickness of approx. 50 µm was formed on the surface of the sample. This layer is depleted of oxygen and has higher electrical conductivity than the interior of the glass. It has also been found that some granules of metallic bismuth with a diameter of tens to hundreds of nanometers were formed on the surface of the glass. Furthermore, depletion of lead was observed in these samples in relation to the initial stoichiometry of the glass prior to trial reduction.

2

Zastosowanie metody PALS do oceny stopnia zdefektowania struktury szkieł tlenkowych ołowiowo-bizmutowo-galowych

Golis E., Filipecki J., Reben M., Wasylak J.

Szkło i Ceramika

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2012

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R. 63, nr 3

26-28

PL

W pracy zaprezentowano badania struktury szkieł tlenkowych ołowiowo-bizmutowo-galowych z wykorzystaniem metody spektrometrii czasów życia anihilujących pozytonów PAL. Obliczone parametry wychwytu pozytonów w badanych szkłach pozwalają wyciągać wnioski dotyczące stopnia i charakteru zdefektowania struktury szkieł. Korelacja otrzymanych wyników z własnościami magnetooptycznymi pozwala na formułowanie hipotez dotyczących wpływu defektów struktury szkieł na ich własności magnetooptyczne. Otrzymane wyniki badań wskazują na postawienie hipotezy, że na własności magnetooptyczne badanych szkieł ma wpływ nie ilość a wielkość defektów oraz istnienie swobodnych objętości w strukturze szkła.

EN

Positron lifetime spectroscopy PALS has been applied to the investigation of lead-bismuth-gallium glass structure. The calculated parameters of positrons trapping in the studied glasses allow to draw conclusions about the defect degree and nature of glass structure. The correlation of obtained results with magneto-optic properties allows to formulate hypotheses concerning the influence of defects in the structure onto their magneto-optical properties. The obtained results of studied glasses suggest that size of defects and the existence of free volume in the glass have significant influence on magneto-optical properties.

3

Ład w bezładzie, czyli kompleksy jonów metali przejściowych w szkłach i żelach tlenkowych

Kłonkowski A.M.

Wiadomości Chemiczne

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1998

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[Z] 52, 1-2

57-85

EN

The most basic difference between crystalline and non-crystalline solids is that a long range order (LORO) in the distribution of atoms (ions) or molecules exists only in crystalline materials [1]. This is indicated by diffraction patterns: the ideal crystal (the first extreme case) shows reflectants whose location and intensity obey three Laue conditions. The second extreme case is an ideally random structure. Scattering of radiation is impossible in the case of an ideally homogenous medium. Any real substance, including non-crystalline materials is inhomogenous regardless of its form or scale. Thus glasses can be thought of as assemblies of microcrystals (i.e. microcrystallites or paracrystals). Strain introduced due to lattice mismatch at grain boundaries, the presence of a disordered interfacial or matrix region, and defects such as dislocation, or stacking faults can be assumed to give rise to departures from periodicity at distances smaller than the average grain size [10]. In this sense glasses are interesting in the supramolecular science because they are intermediate objects in the way from random to organized matter [5]. The object of this article are such amorphous materials as inorganic oxide glasses with structural groups YO4, where Y = Si, P, and organically modified silicate gels. Among the studied glasses are ones of the type : R2O-SiO2 and R2O-Al2O3-SiO2, where R represents alkali atom (Li to Cs) [23, 25, 27], as well as M(II)O-P2O5, where M(II) is an alkaline earth atom (Mg to Ba) [28, 29, 32, 33]. Undoped glasses and those doped with copper (II) ions were investigated. These metal ions have played the role of probes. All the vitreous systems are classified according to their theoretical optical basicity [lambda] cal proposed by Duffy and Ingram [34]. Thanks to this method one can methodically observe and sensibly interpret changes of real measures of basicity as molar refractivity of oxide ions Ro (see Figs 9 and 10a), the so-called Imagawa's basicity (Fig.10b) and other physical and chemical properties of oxide glasses (Fig.11). The studied glasses are also classified according to their bond nature (Fig. 6)., taking into account their proximity to the onset of metallization [4]. Attention is also focused on the mixed alkali effect [22, 24]. A full understanding of the properties of colloids calls upon a wide range of physical and chemical ideas, while the multitude of colloidal systems presented to us in nature, and familiar in modern society, exhibits a daunting complexity. On the experimental side there is an ever-increasing emphasis on the application of modern physical techniques to colloidal problems. Colloid science is thus a truly interdisciplinary subject [3]. In the case of the xerogels there are described Cu(II) complexes existing on surface and in interior of the material [59-63]. Moreover, silica xerogels with immobilized supramolecular ligands show intensive luminescence (Fig. 17) which is effectively quenched by Cu(II) ions [64].