Investigation of Structural, Dielectric, and Optical Behaviour of Dysprosium-Doped Barium Titanate Ceramics

Abstract

The influence of Dysprosium (Dy) doping on the structure, dielectric and optical properties of the BaTiO3 system has been investigated in the manuscript. The solid-state reaction method was employed to prepare ceramics with compositions of Ba1−xDy2x/3TiO3 (x = 0.0, 0.01, 0.025, 0.05, 0.075, and 0.1). X-ray diffraction (XRD) structural analysis was carried out, showing complete dissemination of Dysprosium in the BaTiO3 lattice with a tetragonal symmetry. Close investigation of the XRD pattern revealed the existence of a small secondary phase above x ≥ 0.025. Microstructure was analyzed using scanning electron microscopy, showing that grain growth was suppressed by the incorporation of Dysprosium. Raman spectra further confirmed crystal symmetry and existence of a secondary phase for higher doping concentrations. Dielectric behavior was studied with variations of frequency and temperature. The temperature variant dielectric constant and dielectric loss represent a decrease of dielectric constant and loss with a rise in dysprosium content with a slight variation of transition temperature. Temperature coefficient of capacitance values for all compositions were calculated. The diffusivity parameter for all compositions was obtained using modified Curie-Weiss law and an enhancement in diffusivity was observed with increased dysprosium content. The optical behaviour of the doped samples was studied via UV–visible spectroscopy and the optical band gap was found to decrease with doping.