Tailoring Curie temperature and dielectric properties by changing the doping sites of Y ions in (Ba, Ca)(Zr, Ti)O3 ceramics

Doping rare earth element significantly influences electrical properties of BaTiO3-based ceramics. In this work, Y-doped (Ba0.95Ca0.05)(Zr0.19Ti0.81)O3 (BCZT) ceramics are investigated by comparing the microstructure, dielectric and conduction properties of BCZT with different doping-sites of Y ions, A-site, B-site and A/B-site, respectively. Y ions are successfully incorporated into the BCZT lattice, irrespective of the doping sites. A-site doping has marginal effect on the grain size and Curie Temperature, however, B-site doping leads to a decreased grain size and Curie temperature with doping concentration. For A/B-site doping sample, the grain size and Curie temperature are dependent on doping concentration. Furthermore, the Tc regulation mechanism is discussed based on the average size effect (), variance effect (σ2), the local electric field and tolerance factor (t) theories. This work provides a potential strategy for adjusting Tc and improving dielectric performance by tuning the doping sites and selecting appropriate rare earth elements with suitable size.