Enhanced dielectric and ferroelectric characteristics in Ca-modified BaTiO3 ceramics

Abstract

Synergic modification of BaTiO3 ceramics was investigated by Ca-substitution, and the superior dielectric and ferroelectric properties were determined together with the structure evolution. X-ray diffraction (XRD) analysis demonstrated a large solubility limit above x = 0.25 in Ba1−xCaxTiO3 solid solution where the fine grain structure was observed with increasing x. Room temperature dielectric constant as high as 1655 was achieved in the present ceramics together with the significantly reduced dielectric loss of 0.013 (x = 0.20 at 100 kHz), where the Curie temperature kept almost a constant while other two transition temperatures decreased continuously with increasing x. More importantly, the remanent polarization Pr and dielectric strength Eb were significantly enhanced by Ca-substitution, and the best Pr (11.34 μC/cm2) and the highest dielectric strength Eb (75 kV/cm) were acquired at x = 0.25. The present ceramics should be very desirable for the applications such as high density energy storage devices.