Effect of Dy3+ Substitution on Structural and Dielectric Properties of 0.8BaTiO3-0.2Bi0.5K0.5TiO3 Lead Free Ceramics

Dysprosium (Dy3+) ion substituted 0.8BaTiO3-0.2Bi0.5K0.5TiO3 (here after abbreviated as BTBKT-20) lead free ceramic materials with composition 0.8BNa0.2(Bi0.5(1-x)Dy0.5xK0.5)TiO3 (where x = 0.01,0.03,0.05) were prepared by conventional solid state reaction method and followed by high energy ball milling process. The X-ray diffraction studies confirm the tetragonal structure of the material at the room temperature. Microstructure studies have been carried out with the help of scanning electron microscope. Temperature and frequency dependent dielectric studies indicate that dielectric constant decreasing with the substitution of Dy3+. The substitution of Dy3+ effect the Curie temperature and it is decreasing with increase of Dy3+ substitution. Relaxor behavior is observed in all the Dy3+ substituted samples. Degree of diffuseness is calculated from the modified Curie-Weiss law and it has been found to be increasing with the substitution of Dy. AC conductivity is calculated and it is found to be obey the universal Jonscher’s Power law.