Low loss and high dielectric BaTiO3@Al2O3 Core@Shell novel nanostructures by heteronucleation method

As-purchased BaTiO3, hydrothermally prepared BaTiO3, and BaTiO3@Al2O3 core@shell nanostructures through heteronucleation method were confirmed for structure/microstructure through XRD/ FESEM/HRTEM. High static dielectric constant of 2450 is obtained for BaTiO3@Al2O3 with a very low loss tangent (Tanδ ∼ 0.1), due to the outer thick insulating Al2O3 layer over BaTiO3. Jonscher's law and Modulus spectra show a non-Debye type broad relaxation obeying a modified KWW function for BaTiO3, with no relaxation for BaTiO3@Al2O3, due to the suppression of dipoles by Al2O3. Higher dielectric field strength of ≥ 20 kV/cm was observed for BaTiO3@Al2O3 through the ferroelectric hysteresis loops.