Effect of BiYbO3 Addition with a Small Tolerance Factor on Ferroelectricity and TC in PbZrO3 Ceramics

Perovskite (Pb(1-3x/2) Bix)(Zr(1-3x/4) Ybx)O3 (PZ-BY) ceramics, where x = 0.01-0.10, were synthesized by conventional solid state reaction. The effect of BiYbO3 on crystal structure, phase transitions and electrical properties was studied as a function of composition. The X-ray diffraction (XRD) result indicated that the perovskite structure with orthorhombic symmetry was a major phase for all samples. The pyrochlore phase, identified as Yb0.2Zr0.8O1.9, coexists in PZ-BY ceramics. The influence of instability and a small tolerance factor (t) and the average electronegativity difference () of pure BY on phase formation of PZ-BY ceramic has been discussed. Furthermore, it was found that adding small tolerance factor BiYbO3 compound can stabilize the antiferroelectric (AFE) phase of PZ solid solutions and decreasing t of solid solution can enhance Curie temperature of PZ.