Piezoelectric and elastic properties of ZnF2–PbO–TeO2: TiO2 glass ceramics

Piezoelectric coefficients d33 as well as ultrasonic velocities and elastic coefficients of ZnF2–PbO–TeO2 glasses crystallized with different concentrations of TiO2 (0.5 to 2.0 wt.%) were measured. The contribution to the piezoelectric coefficients is attributed to presence of Pb5Ti3F19, PbTiO3 and PbTeO3 ferroelectric crystal phases. The piezoelectric coefficients show substantial sensitivity to presence of TiO2. The ultrasonic velocities and the related elastic coefficients in these glass ceramics as a functions of concentration of nucleating agent TiO2 exhibited minimal effect at 1.0 wt.%. This is ascribed to the larger presence of titanium ions in Ti3+ states which act as modifiers and finally de-polymerize glass ceramic network. The results have been further discussed quantitatively within a framework of different oxidation states of titanium ions and the nature of the crystal phases ingrained in the glass ceramic.