Structure and microwave dielectric properties of Ba[(Mg 1−x Ni x ) 1/3 Nb 2/3 ]O 3 ceramics

Microwave Dielectric Properties of Low-Loss (1-x) Ca<sub>0.6</sub>Sm<sub>0.267</sub>TiO<sub>3</sub>–xSmAlO<sub>3</sub> Ceramics

“…With increasing content of SmAlO 3 additions the grain sizes tended to become smaller as SmAlO 3 additions suppressed the grain growth and enhanced the densification process, which was analogy with the report by the researchers [12,13]. No significant amount of porosity is observed even at higher concentrations of SmAlO 3 . No evidence of second phases were observed in the SEM micrographs too.…”

“…As the content of SmAlO 3 increased from 0.05 to 0.20, no secondary phase appeared. All samples of the (1-x) Ca 0.6 Sm 0.267 TiO 3 -xSmAlO 3 ceramics exhibited formed perovskite phase system only.…”

“…(1-x)Ca 0.6 Sm 0.267 TiO 3 -xSmAlO 3 (x= 0.05-0.20) microwave ceramics were prepared by solid-state reaction route at 1450°C for 4h for the purpose of investigating effect of SmAlO 3 ratio on the sintering behavior and microwave dielectric properties. As the content of SmAlO 3 increased from 0.05 to 0.20, no secondary phase appeared.…”

“…In all the compositions, additions of rare earth aluminates deteriorate the dielectric constant obviously. The observed change in permittivities is attributed to the low permittivities of the dopants SmAlO 3 . In a similar to the variation in permittivity in Fig.3, as Ca 0.6 Sm 0.267 TiO 3 and SmAlO 3 exhibit positive and negative temperature dependencies of permitivity respectively, a linear decrease with increasing content of the additives of the τ f values was shown in Fig.4.…”

“…Small temperature coefficient of the resonant frequency is required to ensure the stability of the microwave components at different working temperatures. Numerous perovskite-type compounds and their solid solutions have been investgated and applied in microwave frequency devices [2][3][4][5][6]. However, in MW frequency range the number of reported dielectrics with high εr, τ f ~0, and low loss is relatively poor.…”