Structure and property correlation of Ca- and Zr- doped BaTiO₃ for energy harvesting application

Abstract

RoHS introduced by EU in 2006 urged researches to replaced Pb-based piezoelectric materials in electronic devices. Hence, BaTiO₃ was proposed as a potential candidate to replace lead-based piezoelectric materials. In this study, Ca²+ and Zr4+ doped BaTiO₃ were successfully synthesised via conventional solid state method. XRD data show the transition of lattice structure form tetragonal to cubic with space group P4mm and Pm-3m respectively. Then, the lattice parameter and unit cell volume were linearly increased. Rietveld refinement revealed good agreement in observed and calculated pattern with relatively low R-factors and χ2. SEM analysis shown non-uniform microstructural image with mean grain size around 5.134μm - 5.848μm. Doped of Ca²+ and Zr4+ into BaTiO₃ had improve the electrical performance. Ba₀.₈₅Ca₀.₁₅Ti₀.₉Zr₀.₁O₃ shown the highest permittivity value around 9000 and lowest dielectric loss around 0.03 at 90ºC. Hence, high permittivity with minimum loss of Ba₀.₈₅Ca₀.₁₅Ti₀.₉Zr₀.₁O₃ offered high piezoelectricity, suitable for energy harvesting devices.