a State Key Laboratory Breeding Base of Nonferrous Metals and Specific Materials Processing, Guilin University of Technology, Guilin, 541004, China
b Key Laboratory of New Processing Technology for Nonferrous Metal and Materials, Ministry of Education, Guilin University of Technology, Guilin, 541004, China
c School of Material Science and Engineering, Guilin University of Technology, Guilin, 541004, China
Received 25 November 2011. Revised 20 February 2012. Accepted 25 March 2012. Available online 7 April 2012.
Dielectric properties and charge compensation of Li and Co co-doped NiO (LCNO) ceramics prepared by a simple sol–gel route have been investigated. The concentration of Co makes a great influence on microstructure, dielectric properties and charge compensation mechanism of the LCNO ceramics. Grain size of the ceramics increases from 5.6 μm to 7.2 μm with dependence on Co concentration. By using a complex impedance analysis at different temperatures, the samples exhibit an electrically heterogeneous structure, which is responsible for a giant dielectric permittivity. The relationship between the activation energies of dielectric relaxation and conduction and charge compensation mechanism in this system were discussed.
