Improved dielectric properties of CaLa4Ti5O17 ceramics with Zr substitution at microwave frequency

In this paper, the effect of Zr4+ substitution on the dielectric properties of CaLa4Ti5O17 ceramics at microwave frequency by the conventional solid-state method has been studied for application in mobile communication. The diffraction peaks of CaLa4Ti5−xZrxO17 ceramics shifted to lower angle as x increasing from 0 to 0.05 and nearly unchanged with x increasing from 0.05 to 0.07. A maximum relative density of 97.5% TD can be obtained for CaLa4Ti4.95Zr0.05O17 ceramic sintered at 1500 °C for 4 h. A maximum dielectric constant and quality factor (Q × f) of CaLa4Ti4.95Zr0.05O17 ceramic sintered at 1500 °C for 4 h are 55.9 and 15,600 GHz, respectively. A temperature coefficient of resonant frequency (τf) of 4.6 ppm °C−1 can be obtained for CaLa4Ti4.95Zr0.05O17 ceramic sintered at 1500 °C for 4 h.