Phase, microstructure and microwave dielectric properties of Zr-doped SrLa4Ti5-xZrxO17

The effect of Zr+4 substitution for Ti+4 on the phase, microstructure and microwave dielectric properties of compositions in the SrLa4Ti5-xZrxO17 (0 a parts per thousand currency sign x a parts per thousand currency sign 0.1) series was investigated. All the compositions formed single phase ceramics within the detection limit of in-house X-ray diffractometer when sintered in the temperature range 1,450-1,580 A degrees C for 4 h in air. The substitution of Zr+4 for Ti+4 enabled processing of highly dense ceramics with a decrease in temperature coefficient of resonant frequency (tau(f)) from similar to 117 to 70 ppm/A degrees C, dielectric constant (epsilon(r)) from 60.8 to 57.3, with no significant effect on the quality factor. In the present study, optimum properties i.e. epsilon(r) similar to 57.3, tau(f) similar to 70 ppm/A degrees C and quality factor (Q (u) x f (o) ) similar to 9,841 GHz, were achieved for SrLa4Ti4.9Zr0.1O17. The trend of the results demonstrates that further studies with increased Zr+4 content are required to achieve ultra low loss SrLa4Ti5-xZrxO17 ceramics.