Abstract
High-k Ba(4)Sm(28/3)Ti(18)O(54) ceramics with improved microwave dielectric characteristics were successfully fabricated using the one-step reaction sintering (RS) route. The sintering characteristics, microstructure, crystal structure, infrared reflection spectrum, and microwave dielectric characteristics of Ba(4)Sm(28/3)Ti(18)O(54) ceramics prepared by the RS route were systematically investigated. Samples prepared by the RS route exhibited single-phase orthorhombic tungsten-bronze structure and dense microstructure at optimum sintering temperature. Compared with the conventional solid-state (CS) process, the Ba(4)Sm(28/3)Ti(18)O(54) ceramics fabricated by the RS route presented a smaller temperature coefficient (TCF), a higher quality factor (Q × f), and a higher permittivity (ε(r)). The improved microwave dielectric characteristics were highly dependent on the theoretical permittivity, atomic packing fraction, suppression of Ti(3+), and Ti-site bond valence. Excellent combined microwave dielectric characteristics (TCF = -7.9 ppm/°C, Q × f = 9519 GHz, ε(r) = 80.26) were achieved for Ba(4)Sm(28/3)Ti(18)O(54) ceramics prepared by RS route sintered at 1400 °C, suggesting the RS route was a straightforward, economical and effective route to prepare high-performance Ba(4)Sm(28/3)Ti(18)O(54) ceramics with promising application potential.