Effect of sintering temperature and time on microwave dielectric properties of lanthanum tin oxide

This study examines the microwave dielectric properties of La2Sn2O7 ceramics with a view to the use of these ceramics in mobile communication. La2Sn2O7 ceramics were prepared by the conventional solid-state method with various sintering temperatures and times. The highest density obtained, 6.61 g/cm3, was that of La2Sn2O7 ceramic that was sintered at 1,580 °C for 34 h. Dielectric constants (εr) of 13.2–14.4 and quality factors (Q × f) of 34,300–40,500 GHz were obtained by sintering at temperatures in the range 1,520–1,610 °C for 34 h. Dielectric constants (εr) of 10.3–14.4 and quality factors (Q × f) of 15,300–40,500 GHz were obtained using sintering times of 30–38 h at a sintering temperature of 1,580 °C. When La2Sn2O7 was sintered at 1,580 °C for 34 h, a dielectric constant (εr) of 14.4, a quality factor (Q × f) of 40,500 GHz and a temperature coefficient of resonant frequency (τf) of −54 ppm/ °C were obtained.