Physical characteristics of PbO−ZrO2−SiO2:TiO2 glass ceramics embedded with Pb2Ti2O6 cubic pyrochlore crystal phase: Part-II piezo-optical acoustic and elastic properties

Abstract

Comprehensive studies on piezo-optical (elasto optical) effects stimulated by bicolor coherent treatment using Er:glass laser, at λ = 1540 nm and its second harmonic generation (λ = 770 nm) insitu with mechanical stress, ultrasonic velocities and elastic coefficients of PbO−ZrO2−SiO2: TiO2 glass ceramics were carried out as a function of concentration of crystallizing agent TiO2. The contribution to the piezo-optical effects is attributed to Pb2Ti2O6 pyrochlore crystal phases appeared in the glasses during crystallization. The observed piezo-optical effects are attributed to simultaneous interference of the contributions due to the induced gratings (because of the bicolor treatment) and the piezo-optically originated birefringence. The variation of piezo optical coefficients, ultrasonic velocities and various elastic coefficients viz., Young's modulus, shear modulus, micro hardness etc., with the concentration of TiO2 exhibited the maximal effect at 0.6 mol% content of TiO2. From the quantitative analysis these results together with the results of other studies (viz., XRD, SEM, EPR, IR, optical absorption spectral studies), it is predicted that the PbO−ZrO2−SiO2 glass crystallized with 0.6 mol% of TiO2 is embedded with higher concentration of Pb2Ti2O6 pyrochlore crystal phases (a crystal phase consisting of Ti4+ ions) and such crystal phases are found to be responsible for observed maximal effects of all the mentioned properties for this sample.