Effect of Zr⁴⁺ on the properties of layered structured Ba(Ti_1−xZr_x)₄O₉ perovskites

ABSTRACT

Solid solutions of Ba(Ti_1−xZr_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 (ϵ_r) 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 ϵ_r 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(Ti_0.8Zr_0.2)₄O₉ ceramics sintered at 1300°C for 2 h in air.

KEYWORDS:

• Dielectrics
• layered perovskites
• mixed oxides
• lead free

Acknowledgment

The authors acknowledge the technical support provided by the Centralized research laboratory (CRL) and Materials research laboratory (MRL), University of Peshawar, Pakistan.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

Note: a, b and c = lattice parameters.

Note: ρ_a =experimental density, ρ_t= theoretical density, ρ_r= relative density.