Nonlinearities in ferroelectric, piezoelectric, and dielectric behavior of Hf incorporated BaTiO3 nontoxic electroceramics

Abstract

We report the structural, ferroelectric, piezoelectric, and dielectric properties of BaTi1−xHfxO3(x = 0, 0.04, 0.08) abbreviated as BT, BHT 1, and BHT-2 lead-free ceramics prepared by solid-state reaction. X-ray diffraction and Raman analysis confirm the formation of tetragonal lattice symmetry with a P4mm space group for studied compositions at room temperature. The tetragonality i.e. c/a ratio and average grain size found to be decreased with Hf4+ incorporation into BaTiO3 (BT). The nonlinearities in dielectric, ferroelectric and piezoelectric properties were observed with Hf4+ incorporation into BT, with the diffuse phase transition (DPT) for BaTi0.96Hf0.04O3 (BHT-1) ceramic, showing improved bulk density ~ 5.90 g/cm3, lattice strain ~ 0.168%, Pr ~ 9.03 μC/cm2, Ec ~ 3.44 kV/cm, Pmax ~ 17.42 μC/cm2, em ~ 7391, Jmax ~ 4.52 × 10–3 A/cm2, d33 ~ 212 pC/N, diffuseness parameter γ ~ 1.58, with relatively higher Curie temperature (TC ~ 125 °C) than pure BaTiO3 a promising candidate for lead-free ferroelectric memory storage (Fe-RAM) and piezoelectric transducers application.