Microstructures, electrical behavior and energy-storage properties of Ba0.06Na0.47Bi0.47TiO3-Ln1/3NbO3 (Ln = La, Nd, Sm) ceramics

• BNBT-Ln1/3NbO3 (Ln = La, Nd, Sm) ceramics were investigated for the first time.
• A maximum energy storage density up to1.239 J/cm3 at 100 kV/cm was exhibited.
• The dispersion behavior and relaxation processes were discussed in detail.

The microstructures and electrical properties of a series of (1-x)Ba0.06Na0.47- Bi0.47TiO3-xLn1/3NbO3(Ln = La, Nd and Sm) ceramics prepared by the conventional solid-state reaction method were investigated. The XRD analysis revealed that all the investigated ceramics have a pure perovskite structure. A maximum energy storage density up to 1.239 J/cm3 at 100 kV/cm was exhibited for 0.98Ba0.06Na0.47Bi0.47TiO3- 0.02Sm1/3NbO3 ceramics. The activation energies of carrier migration and relaxation process in the ceramics showed nearly similar values of ∼1.0eV. The diffusion factor γ corresponding to Ln = La, Nd and Sm at a frequency of 100 kHz were estimated to be 1.96, 1.89 and 1.91, respectively. Detailed studies on dielectric spectroscopy revealed a relaxor behavior with diffuse phase transition in these ceramic systems. The general approach to equivalent circuit model of BNBT-xLnN ceramics has been used to interpret spectra obtained from impedance measurements. By additional use of the complex electric modulus formalism to analyze the same impedance data, the dispersion behavior and temperature-dependent relaxation processes of the ceramics may be probed.

Polarization hysteresis loops of BNBT-xLnN ceramics under 60kv/cm: (a) Ln = La; (b) Ln = Nd and (c) Ln = Sm. And (d) polarization hysteresis loops of BNBT-0.02LnN ceramics.Figure optionsDownload as PowerPoint slide