Elastic, thermoluminescence and dielectric characterization of lead antimony silicate glass composites doped by small concentrations of $\hbox {Cr}_{{2}}\hbox {O}_{{3}}$

Abstract

A series of glass composites [($\hbox {Sb}_{{2}}\hbox {O}_{3})_{0.05}(\hbox {SiO}_{2})_{0.65}$]–[$\hbox {(PbO)}_{(0.3-x)}$:($\hbox {Cr}_{{2}}\hbox {O}_{3})_{x}$] ($0 \le x \le 0.01$ mol%) were synthesized. Elastic, thermoluminescence, direct current (dc) conductivity and dielectric characteristics of these glass composite materials were studied. The investigations on these glass composites have indicated that the chromium ions exhibit two different oxidation states, such as $\hbox {Cr}^{3+}$ and $\hbox {Cr}^{6+}$. The variation in poison ratio ($\sigma$) with micro-hardness (H) plots suggests that the glass composites were prepared with a strongly and covalently connected internal structure. The observed thermoluminescence output increased with an increase in the dose of UV-irradiation. The observed peak positions of these thermoluminescent curves were shifted towards higher temperature regions. The enhanced thermoluminescence output results even recommended that both $\hbox {e}^{-}$ and $\hbox {h}^{+}$ trap cantres were created at the deeper trap levels and contribute to thermoluminescence emissions at higher temperatures. The dc conductivity $(\sigma _{\mathrm{dc}})$ and activation energy evaluations are also observed. Dielectric parameters such as density of energy states ${N}(E_{\mathrm{f}})$, temperature region of relaxation and loss tangent (tan $\delta$) were calculated. The linear relationship between variation in alternating current conductivity ($\sigma _{\mathrm{ac}}$) and activation energy suggests that good amounts of polaron hopping with an increase in $\hbox {Cr}_{{2}}\hbox {O}_{{3}}$ concentration in these materials were observed. The grades of loss tangent and the number of energy states near the Fermi level suggest that the materials prepared are highly useful in dielectrics.