Role of O 2p-Ti 3d orbital hybridization in dielectric and ferroelectric properties of barium zirconate titanate ceramics

Abstract Barium zirconate titanate (BaZryTi1-yO3) ceramics for y = 0.10, 0.15 and 0.20  were synthesized using conventional solid-state method to study the effect of O 2p-Ti 3d orbital hybridization on dielectric and ferroelectric properties. X-ray diffraction, transmission electron microscopy and Rietveld refinement show structural phase transition from tetragonal P 4 m m to cubic P m 3 ¯ m with increasing Zr concentration. Dielectric permittivity and Raman spectra show enhanced relaxor behavior which is attributed to decreased O 2p-Ti 3d orbital hybridization as Zr doping increased. Lattice distortion due to decreased O 2p-Ti 3d orbital hybridization induced by Zr doping caused lattice strain mismatch contributing to enhancement of dielectric permittivity. Reduced ferroelectric instability due to decreased Ti-O covalency with increasing Zr significantly reduced P r values. Temperature dependent P-E loops shows increased W r e c and η implying no energy dissipation and good thermal stability of BZT perovskites even at elevated temperatures which is beneficial for energy storage applications.