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 BaTiO 3 system has been investigated in the manuscript. The solid-state reaction method was employed to prepare ceramics with compositions of Ba 1−x Dy 2x/3 TiO 3 (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 BaTiO 3 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.