Zero-Temperature Coefficient of Resonant Frequency in [(Mg0.6Zn0.4)0.95Co0.05]1.02TiO3.02-Ca0.6(La0.9Y0.1)0.2667TiO3 Ultra-Low-Loss Composite Dielectrics

Abstract

Investigating the microwave dielectric properties of ceramics prepared through the conventional solid-state route, such as x[(Mg0.6Zn0.4)0.95Co0.05]1.02TiO3.02-(1−x)Ca0.6(La0.9Y0.1)0.2667TiO3, reveals notable characteristics. [(Mg0.6Zn0.4)0.95Co0.05]1.02TiO3.02 shows a permittivity (εr) of approximately 20, a high quality factor (Q × f) ranging between 250,000 and 560,000 GHz, and a temperature coefficient of resonant frequency (τf) of approximately −65 ppm/°C. To enhance the temperature stability, Ca0.6(La0.9Y0.1)0.2667TiO3 featuring a τf value of +374 ppm/°C was incorporated into the [(Mg0.6Zn0.4)0.95Co0.05]1.02TiO3.02 composition. τf demonstrated an increase with rising Ca0.6(La0.9Y0.1)0.2667TiO3 content, reaching zero at x = 0.95. A ceramic composition of 0.95[(Mg0.6Zn0.4)0.95Co0.05]1.02TiO3.02-0.05Ca0.6(La0.9Y0.1)0.2667TiO3, incorporating 3wt.% BaCu(B2O5) as sintering aids, exhibited outstanding microwave dielectric properties: εr~22.5, Q × f~195,000 (at 9 GHz), and τf~0.1ppm/°C, with a sintering temperature at 950 °C. This material is proposed as a prospective candidate for 6G band components and GPS antennas.