Microstructural, Pyroelectric and Energy Storage Performance of Rare Earth-Doped Ba_0.15R_0.04Ca_0.15Zr_0.1Ti_0.9O₃ Ceramics

Abstract

In this article, the microstructural, pyroelectric and energy storage performance of rare earth-doped lead-free ceramics, namely (BaTiO₃ based) Ba_0.15R_0.04Ca_0.15Zr_0.1Ti_0.9O₃ (BCZTO-R; R=Ce, Nd and Ho) is investigated. The Ce, Ho and Nd were taken as the rare earth dopant in pristine BCZTO ceramics. Structural analysis indicated that the samples were in a single perovskite phase as there were no secondary peaks observed in X-ray diffraction analysis. Microstructural observation indicates the well densification with bimodal grain size distribution suggesting that the larger grains grew at the expense of smaller grains. The pyroelectric performance of the pure ceramic and rare earth-doped BCZTO was evaluated based on experimental observations. The pyroelectric coefficient improved from 10 × 10⁻⁴ to 14 × 10⁻⁴ C/cm² at their phase transition temperature. However, the pyroelectric coefficient increased from 3 to 4.6 at room temperature for Nd-doped BCZT. Also, on exposure to the transient temperature gradient, the Nd-doped sample had a higher open-circuit voltage of 685 mV when compared with 465 mV in base ceramic under consideration. The figure of merits (FOMs) for voltage responsivity (F_v), current responsivity (F_i), detectivity (F_d) and energy harvesting (F_e and F_e*) was evaluated for samples. Further, the energy storage performance also increased for Nd-doped specimen over pure ceramic. All these improvements could possibly replace its lead-based counterparts for pyroelectric applications. We have also preprocessed our laboratory data for removing noises and to get more accurate results also a computer program is proposed that can reproduce our experimental work and can be used to find out how much voltage the ceramic can produce when kept under a particular temperature gradient. On Validating our programmatic data with the experimental data we observed that the results are in close proximity to the experimental data.