Jahn-Teller assisted polaronic electron hopping in LiCuNb3O9

• Published in: Journal of the European Ceramic Society Vol. 41; no. 4; pp. 2625 - 2632
• Main Authors: Ahmed, R., Wang, J., Si, R.J., Rehman, S. ur, Li, T., Bi, H., Yu, Y., Li, Q.J., Li, Y.D., Huang, S.G., Guo, Y.M., Wang, C.C.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-04-2021
• Subjects: Humidity sensitivity; Impedance analysis; Jan-Teller effect; Maxwell-Wagner relaxation; Polaron hopping; Humidity sensitivity; Maxwell-Wagner relaxation; Polaron hopping; Impedance analysis; Jan-Teller effect
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/j.jeurceramsoc.2020.11.034

The role of A-sited elements in double perovskite colossal dielectric LiCuNb3O9 has been analyzed by replacing the Cu ions with Li ions. Structural analysis revealed the presence of Jahn-Teller effect because of the Cu ions. Two thermally activated relaxations have been observed: the lower temperature one has been assigned to be a polaronic relaxation following Mott variable-range-hopping mechanism. Impedance analysis and humidity sensitive test proved that the higher temperature one is a Maxwell-Wagner relaxation. Our work highlights that the polaronic hopping is responsible for the colossal dielectric permittivity behavior of LiCuNb3O9.