engleski

The use of windowing polarization for the study of multi-component glass

An attempt was made to investigate the possibility of applying thermally stimulated depolarization current (TSDC) techniques to the analyses of multi-component glass with a different relaxation mechanisms. Therefore multi-component borosilicate glass containing the addition of Li2O, Na2O, MgO, BaO or in some cases Fe2O3, was investigated by integral and by partial TSDC measurements. Except for usual partial peaks, which follow the applied poling window  Tp, some additional peaks appeared independently of  Tp. By the consideration of temperature of the partial peaks maxima, vs. the temperature of poling it was possible to map and separate different and overlapping events. Generally, in the range from 170 to 320 K several processes were observed. Po with maximum at 198 &plusmn ; ; ; 2 K caused by the space charge, P1 at 228 &plusmn ; ; ; 3 K and P2 at 263 &plusmn ; ; ; 4 K caused by dipolar relaxations. The windowing technique shows a higher temperature process P3 at about 285 - 330 K attributed to the Wagner-Maxwell effects. Special attention was paid to the appearance of a number of single-relaxation time processes in the range of P2 caused by the interaction between the divalent ions and the vacancies. Glass with Fe2O3 showed a decrease in distribution width in P1 and P2 ranges, which corresponds to an increase in homogeneity of the system. The addition of Fe2O3 also increased the magnitude of the depolarized current. The additional heat treatment of glass increased the number of the single-relaxation time processes.

borosilicate glass; thermally stimulated current; TSDC

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