Effect of Zr4+ on the properties of layered structured Ba(Ti1−x Zr x )4O9 perovskites

Abstract

ABSTRACT Solid solutions of Ba(Ti1−x Zr x )4O9 (0 ≤ x ≤ 0.8) were fabricated via mixed oxides, solid state route. The phase, microstructural and dielectric properties of the fabricated samples were investigated. A structural phase transition was observed from orthorhombic (Amm2) to tetragonal (P4/mmm) with increasing Zr4+ contents (x ≥ 0.6). The dielectric constant (ϵr ) increased with the substitution of Zr4+ contents which may be attributed to the larger ionic size and higher polarisability of Zr4+ relative to Ti4+. The maximum ϵr of 48.27 was observed for x = 0.2. The lowest dielectric loss (tan δ) of 5.5 × 10−4 and maximum quality factor (Q × f) of 5.6 × 104 MHz were obtained (at 30 MHz) for Ba(Ti0.8Zr0.2)4O9 ceramics sintered at 1300°C for 2 h in air.