Enhanced dielectric and electrocaloric properties in lead-free rod-like BCZT ceramics

Ba0.85Ca0.15Zr0.10Ti0.90O3（BCZT） lead-free ceramics demonstrated excellent dielectric, ferroelectric, and piezoelectric properties at the morphotropic phase boundary（MPB）. So far, to study the effect of morphological changes on dielectric and ferroelectric properties in lead-free BCZT ceramics, researchers have mostly focused on the influence of spherical grain shape change. In this study, BCZT ceramics with rod-like grains and aspect ratio of about 10 were synthesized by surfactant-assisted solvothermal route. X-ray diffraction（XRD） and selected area electron diffraction（SAED） performed at room temperature confirm the crystallization of pure perovskite with tetragonal symmetry. Scanning electron microscopy（SEM） image showed that BCZT ceramics have kept the 1 D rod-like grains with an average aspect ratio of about 4. Rod-like BCZT ceramics exhibit enhanced dielectric ferroelectric（εr = 11,906, tanδ = 0.014, Pr = 6.01 μC/cm2, and Ec = 2.46 k V/cm）, and electrocaloric properties(ΔT = 0.492 K and ζ= 0.289（K·mm）/kV at 17 kV/cm) with respect to spherical BCZT ceramics. Therefore, rod-like BCZT lead-free ceramics have good potential to be used in solid-state refrigeration technology.