Structural, electrical, and optical properties of (Ba_1−xNd_2x/3)TiO₃ ceramics

Abstract

In this paper, we report the obtention of barium neodymium titanate (Ba_1−xNd_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.

Keywords:

• barium titanate
• neodymium
• Rietveld
• dielectric
• photoluminescence

Acknowledgments

The authors M. Ganguly, S.K. Rout, and P.K. Barhai gratefully acknowledge the financial support of major research project [39-865/2010(SR)] funded by the UGC, Government of India.