Phase Character and Dielectric Properties of Amphoteric Holmium‐Doped Ba0.90Ca0.10(Ti0.95Zr0.05)2O5 Polycrystalline Ceramics

Amphoteric rare‐earth ion dopants can improve ferroelectric ceramic electrical performance because of their amphoteric ion radius and valences. Herein, Ho3+‐doped Ba0.90Ca0.10(Ti0.95Zr0.05)2O5 ceramics are sintered at 1230 °C with as‐synthesized nanoparticles. The effects of various holmium contents (x) on the phase, structure, dielectric, and piezoelectric characteristics are investigated. For low x ( 1.5 mol% because of the re‐emerged oxygen vacancies and interrupted long‐range ordering with large compositional fluctuations. The defect chemistry mechanism at different x contents is deduced in accordance with the phase and electrical properties. The activation energy initially elevates to 1.56 eV and then decreases to 1.35 eV with increasing x. Results indicate that the ceramics are promising candidates for lead‐free ferroelectric ceramics. Herein, a novel strategy for preparing high‐densified holmium‐doped Ba0.90−xCa0.10Hox(Ti0.95Zr0.05)2O5 (BC(ZT)2−xHo) polycrystalline ceramics with as‐synthesized nanoparticles that are synthesized via a modified Pechini polymeric precursor method is provided. The defect chemistry mechanism is deduced for elucidating various dielectric and ferroelectric properties. BC(ZT)2−xHo ceramics features high insulating character and good ferroelectricity, suggesting that they are potential lead‐free ferroelectric materials candidates.