Structural, electrical, and optical properties of (Ba_1−x Nd_2x/3)TiO₃ ceramics

In this paper, we report the obtention of barium neodymium titanate (Ba_1−x Nd_2x/3)TiO₃ ceramics with (0.00 ≤ x ≤ 0.10) by the solid-state reaction method. Structural studies suggested a phase transition from tetragonal to cubic structure with increase in Nd³⁺ ion content, supported by Rietveld refinement method. Photoluminescence properties revealed that the introduction of Nd³⁺ ions created structural disorder by means of A-site vacancies and displacement of M–O bond leading to shallow defects. Optical band gap value calculated from ultraviolet–visible spectra decreased with increase in Nd³⁺ ion concentration. A drastic decrease in grain size of undoped barium titanate was observed with introduction of Nd³⁺ ions through scanning electron microscopic images. Dielectric properties showed a gradual decrease in the Curie temperature with increase in Nd³⁺ ion content along with pinching effect. Normal ferroelectric character was obtained within the doping limit. P–E hysteresis loop showed a decrease in remnant polarization and coercive field. However, the composition x = 0.08 and 0.10 showed paraelectric behavior.