Improving τf and thermal conductivity of Ba(Zn1/3Nb2/3)O3 microwave dielectric ceramics by ordered domain engineering

The effects of B-site 1:2 ordering and ordered domain structure upon temperature coefficient of resonant frequency and thermal conductivity were systematically investigated for Ba(Zn1/3Nb2/3)O-3 microwave dielectric ceramics. These characteristics could be significantly improved by the means of ordered domain engineering. The temperature coefficient of resonant frequency apparently reduced with increasing ordering degree (from 32.07 ppm/degrees C for disordered samples to 28.03 ppm/degrees C for samples with ordering degree of 0.886), while the thermal conductivity significantly increased (from 3.23 W m(-1) K-1 to 3.72 W m(-1) K-1) at room temperature. The increased thermal conductivity resulted from the reduced phonon scattering, while the improved temperature coefficient of resonant frequency was due to the increased bond covalency, which contributed to the decreased tau epsilon${{{\tau}}_{\rm{\varepsilon }}}$. The present results will provide an efficient way to improve the performance of microwave dielectric ceramics for resonator applications for 5G mobile communication system.