Sintering behaviour and microwave dielectric properties of a new complex perovskite: ($1−x$)(Sr$_{0.3}$Ca$_{0.427}$Nd$_{0.182}$)TiO$_{3−x}$SmAlO$_3$ ceramics

Bulletin of Materials Science

关键词: (Sr$_{0.3}Ca$_{0.427}$Nd$_{0.182})TiO$_3$;    SmAlO$_3$;    microwave dielectric properties;    oxygen octahedral distortion.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Structural features and microwave dielectric properties of ($1−x$)(Sr$_{0.3}$Ca$_{0.427}$Nd$_{0.182}$)TiO$_{3−x}SmAlO$_{3}($0.05 \le x \le 0.4$) ceramics were investigated. X-ray diffraction patterns illustrated that solid solutions with the orthorhombic perovskite were shown to be formed in the ranges of $0.05 \le x \le 0.4$. Moreover, the dielectric constant ($\epsilon_r$) of sintered ceramics had a quasi-linear decrease with the increase in SmAlO$_3$ content. A certain amount of Sm and Al substitution for A- and B-sites could substantially improve the quality factor ($Qf$) of the ceramics. Increasing the oxygen octahedral distortion led to a decrease in the temperature coefficient of the resonant frequency ($\tau_f$) from 216.3 to $−$34.8 ppm $^{\circ}$C$^{−1}$. Additionally, optimized microwave dielectric properties can be achieved for the specimens using 0.75(Sr$_{0.3}$Ca$_{0.427}Nd$_{0.182}$)TiO$_3$–0.25SmAlO$_3$ ceramics [$\epsilon_r \sim 58.3$, $Qf \sim 18800$ GHz (at 4.65 GHz) and$\tau_f \sim 2.3$ ppm $^{\circ}$C$^{−1}$] after being sintered at 1500$^{\circ}$C for 4 h.

【 授权许可】

CC BY