Dielectric properties of A and B-site doped LaTiO3−δ perovskites synthesised by sol–gel method

摘要

In this paper, we report the temperature dependent dielectric properties of A-site and B-site doped LaTiO3−δ nanoceramic perovskites prepared by the sol–gel method. X-ray diffraction patterns confirmed a single phase with orthorhombic structure for all doped and undoped perovskites. The grain morphology observation by scanning electron microscope shows well defined grains. The oxidation states of La3+ and Ti3+ ions have been established using X-ray photoelectron spectroscopy. Impedance spectroscopy revealed that dielectric constant and dielectric loss of A-site and B-site doped LaTiO3−δ are temperature independent at higher frequency region whereas temperature dependent in the lower frequency region. The A-site doped perovskite exhibited a higher dielectric constant (έ) of 1,500, whereas B-site doped LaTiO3−δ exhibited 900 at 100 Hz.