Sintering characteristics and microwave dielectric properties of a new temperature-stable ceramic of Ce0.5Sm0.5O1.75.

The novel temperature-stable microwave dielectric ceramics of Ce_0.5Sm_0.5O_1.75 were fabricated via the mixed oxide reaction method, with the detail information including crystal phase, microstructure, sintering behavior and microwave dielectric properties being systematically investigated. For crystal phase, all the diffraction patterns were indexed as cubic fluorite-type structure with Fm-3m (225) space group and exhibited a single phase with no obvious peak position shift. The grain growth was analyzed by density and average grain size. For microwave dielectric properties of Ce_0.5Sm_0.5O_1.75 ceramics, the dielectric constant value (ε_r) was dependent on density. The quality factors (Q × f values) were investigated considered with average grain size. And the temperature coefficient of resonant frequency (τ_f value) had no significant change during the sintering temperature range, which was found consistent with the trend of the dielectric constant value. The Ce_0.5Sm_0.5O_1.75 ceramics sintered at 1475 °C for 4 h exhibited good microwave dielectric performances with ε_r = 18.21, Q × f = 70,500 GHz, and τ_f = − 16.4 ppm/°C. [ABSTRACT FROM AUTHOR]