Synthesis, characterization and dielectric properties of xBaTiO-(1 − x)BaSmTiO.

Temperature stable microwave dielectric materials xBaTiO-(1 − x)BaSmTiO were produced through a conventional solid-state reaction procedure in the work. The structural and microwave dielectric properties of the ceramics were determined with the purpose of finding a microwave ceramics with high dielectric constant (ε), high quality factor (Q × f) and zero temperature coefficient of resonant frequency (τ). Experimental results showed that BaTiO additions affected grain growth and densification, the grain size distribution, and tuned the dielectric properties of the produced ceramics. The amount of BaTiO strongly influenced the densification and the microstructure (i.e. grain shape and size) of the produced ceramics. Analysis of the experimental results suggests that the microstructural features can be correlated to the dielectric properties of these ceramics. Accordingly, the dielectric constant (ε) and the temperature coefficient of resonant frequency (τ) of the produced BaSmTiO ceramics can be tuned with the amount of BaTiO additions and the sintering process parameters. The best dielectric properties were achieved for BaSmTiO ceramics with 15% BaTiO (ε = 66, Q×f = 15,730 GHz and τ ≈ 0 ppm/°C). Experimental results suggest that BaTiO doping improves the dielectric properties of the sintered BaSmTiO perovskite ceramics, which are further enhanced by doping with BaTiO in small amounts. However, further increase of BaTiO content jeopardizes them. [ABSTRACT FROM AUTHOR]