Effect of particle size and ZnO addition on microwave dielectric properties of nanocrystalline (Zr 0.8 Sn 0.2 ) TiO 4 ceramics

Polycrystalline samples of (Zr_0.8Sn_0.2)TiO₄ have been synthesised by solid state reaction method. The effects of ball milling and the addition of ZnO (1–2.5 wt-%) on the microwave dielectric properties of (Zr_0.8Sn_0.2)TiO₄ ceramics are investigated. As the ball milling time increases, the density of the (Zr_0.8Sn_0.2)TiO₄ ceramics increases. The influence of ZnO as a sintering aid on the sintering temperature of (Zr_0.8Sn_0.2)TiO₄ is also studied. As the weight percentage of ZnO increases, the density increases up to 1.5 wt-% of ZnO and thereafter it starts decreasing. The dielectric constant εγ _r and the product of quality factor Q and resonant frequency f_o of TE_{01 °} mode (Qxf_o) followed the same trend with increasing density, irrespective of whether the density increased with ball milling time or by addition of ZnO. The value of Qxf _o is found to increase with increasing grain size. The microwave dielectric constant and the Qxf _o values were respectively ranged from 32 to 39.3 and from 32 000 to 49 600 at 10.5 GHz for (Zr_0.8Sn_0.2)TiO₄ ceramics. Furthermore, the influence of the processing parameters on the microwave dielectric properties of (Zr_0.8Sn_0.2)TiO₄ is discussed.