Effect of ZrO2 on dielectric; optical and structural properties of yttrium calcium borosilicate glasses

In the present investigation, 30SiO(2)-30B(2)O(3)-10Y(2)O(3)-(30-x)CaO-xZrO(2) (x=2.5, 5,7.5, 10) system has been synthesized by melt-quench technique. The as quenched samples are characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UV visible spectroscopy and impedance analyzer. Modification in local glassy units by ZrO2 instead of CaO leads to change optical and dielectric properties. As ZrO2 content increases optical band gap decreases from 3.84 eV (x=2.5) to 3.74 eV (x=10). The transmittance of infrared radiation increases with increasing ZrO2 content. The dielectric loss (Tan delta) of all the samples is less than 2% up to 500 degrees C at 1 MHz. The lowest dielectric constant (similar to 12) is observed for x=7.5 with excellent temperature and frequency stability.