Crystal structure, dielectric, ferroelectric and energy storage properties of La-doped BaTiO3 semiconducting ceramics

Abstract

Polycrystalline La-doped [Formula: see text] [Formula: see text] [[Formula: see text]] ceramics (denoted as BTO,BLT1,BLT2,BLT3) were synthesized by conventional solid-state reaction method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman spectroscopy. XRD and Raman spectra revealed single-phase tetragonal perovskite crystalline structure. Well-saturated polarization–electric field ([Formula: see text]) hysteresis loops were observed with the measurement frequency of 50 Hz at room temperature and confirmed ferroelectric nature of these ceramics and a high recoverable electrical energy storage density of 0.350 J/cm3 with energy efficiency [Formula: see text], which is useful in energy storage capacitor applications. Dielectric studies revealed anomalies around 415–420 K and near the Curie temperature. The latter is attributed to the ferroelectric to paraelectric phase transition. Better dielectric performances were obtained for La-doped samples sintered at 1350°C for 4 h. Grain growth is inhibited with lanthanum (La) incorporation into the BTO lattice. Room temperature semiconducting behavior with positive temperature coefficient of resistivity (PTCR) behavior at [Formula: see text] is attributed to electron compensation mechanism.