Abstract Effect of praseodymium (Pr3+) substitution at Ca2+ site in calcium copper titanate, CaCu3Ti4O12 (CCTO), has been investigated. Compositions with x=0.10 and 0.20 were synthesized in the system Ca(1−3x/2)PrxCu3Ti4O12 by chemical route. Crystal structure is remained cubic. X-ray diffraction and field-emission scanning electron macrographs indicate the presence of secondary phases such as CaTiO3 and CuO. X-ray photoelectron spectroscopy suggests the substitution of Ca2+ by Pr3+/Pr4+. Low temperature admittance spectroscopy identified two deep trapping levels at 0.098 and 0.073 eV for x=0.20 and 0.078 and 0.060 eV for x=0.10. High temperature impedance spectroscopy shows that the grain boundary potential is 0.40 eV and 0.48 eV for x=0.20 and x=0.10 samples respectively. Pr3+ doping decreases dielectric loss in the bulk at low temperature but increases the dc leakage due to the lower value of grain boundary potential.
A. Kumar Rai, Gim, J., Shin, E. -chol, Seo, H. - H., Mathew, V., Mandal, K. D., Parkash, O., Lee, J. - S., and Kim, J., “Effects of praseodymium substitution on electrical properties of CaCu 3 Ti 4 O 12 ceramics”, Ceramics International, vol. 40, pp. 181 - 189, 2014.