Abstract
Abstract Incorporation of Nb and Co and formation of dielectric ceramics were studied in ceramics of the system BaTiO 3 -Nb 2 O 5 -Co 3 O 4 . Temperature-stable dielectric materials of the specification ‘X7R’ were found, showing permittivities up to K ≅ 4800. The slow volume diffusion of Nb favours the formation of ‘core-shell’ structures in BaTiO 3 which are responsible for the temperature-stability. Pentavalent Nb and divalent Co show a pronounced co-solubility in BaTiO 3 . At the atomic ratio Nb:Co = 2:1 semiconductive materials occur which show the PTCR effect. The ratio of Nb:Co = 2:1 strongly suggests charge compensation of [Nb 5+ ]-donors by [Co 2+ ]′'-acceptors on Ti sites, forming the complex [Nb 5+ 2/3 Co 2+ 1/3 ] 4+ . The insulation resistance and life stability of thin dielectric layers of BaTiO 3 -Nb, Co X7R material are determined by the interconnection of lower insalating undoped BaTiO 3 cores. The percolation limit depends on the dispersal of Nb 2 O 5 and Co 3 O 4 over the BaTiO 3 .
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
