Dielectric and electrical conductivity characteristics of undoped and samarium doped ferroelectric SrBi₂Ta₂O₉ ceramics derived from molten salt synthesis route

ABSTRACT

Undoped and samarium doped SrBi₂Ta₂O₉ ferroelectric ceramics have been fabricated by the molten salt synthesis route. The dielectric and electrical conductivity measurements were carried out in the 100 Hz – 1 MHz frequency range at various temperatures. A decrease in dielectric constant maximum (ϵ_m) and a downward shift in the Curie transition temperature (T_c) have been observed with the increase in samarium concentration.The frequency dependence real and imaginary parts of dielectric constant of these ceramics exhibited low frequency dielectric dispersion. Interestingly, temperature and frequency dependence dielectric constant plots indicated that the formation of oxygen ion vacancies have inhibited by samarium doping in SBT lattice. The activation energy values obtained from the Arrhenius plot have confirmed the existence of motion of oxygen ion vacancies in these ceramics.

KEYWORDS:

• Strontium bismuth samariumtantalate
• dielectric properties
• phase transition
• frequency dependence

Acknowledgments

The authors thank Alagappa University, Karaikudi, India and Karunya University, Coimbatore, India for their assistance in characterization.

Funding

This work was supported by Department of Science and Technology (Project No: SR/FT/CS-065/2009), India.