Study of the structure–property relationship in Ba substituted CaLa4Ti5O17 ceramics
Ca1−xBaxLa4Ti5O17 (0 ≤ x ≤ 0.2) compositions were fabricated via a solid-state mixed oxide route and their phase, microstructure and microwave dielectric properties were investigated. All the compositions formed single phase in the Ca1−xBaxLa4Ti5O17 (0 ≤ x ≤ 0.2) solid solutions within the detection limit of in-house X-ray diffraction. The sintered microstructure of these ceramics comprised densely packed elongated and plate-like grains. The dielectric properties varied linearly with increasing x content. Relative permittivity (ε r ) increased from 53.2 to 56.6, Q u f o decreased from 14,600 to 12,630 GHz and τ f was tuned through zero and increased from −33.6 to 1.4 ppm/°C with increase in x value from 0 to 0.2. In the present study, εr ≈ 56.6, Q u f o ≈ 12,630 GHz and a near zero τf ≈ 1.4 ppm/°C was achieved for Ba0.2Ca0.80La4Ti5O17 (x = 0.2) ceramics.
KeywordsSinter Temperature Structural Phase Transition Microwave Dielectric Property Dielectric Resonator Composition Series
The authors acknowledge the financial support extended by the Higher Education Commission of Pakistan under International Support Initiative Programme (IRSIP). The authors also acknowledge the laboratory support extended by Prof. I M Reaney and the electro-ceramics group, Department of Material Science and Engineering, University of Sheffield (UK).
- 1.M. Reaney, D. Idles, J. Am. Ceram. Soc. 89, 2068 (2006)Google Scholar