Abstract
We investigated the effects of the re-oxidation temperature and time on the positive temperature coefficient (PTC) of resistivity characteristics of Sm-doped BaTiO₃ sintered at 1200~1260℃ for 2 h in a reducing atmosphere (3% H₂/N₂), followed by re-oxidization processes in air, in which re-oxidization temperature and time were 600~1000℃ and 1~10 h, respectively. The result reveals that Smdoped (Ba,Ca)TiO₃ ceramics fired in a reducing atmosphere exhibit low PTC characteristics, whereas the sample re-oxidized at 800℃for 1 h in air exhibit pronounced PTC characteristics. The room-temperature resistivity and jumping characteristics of resistivity (ρmax/ρ 25℃ ) decrease with Sm contents. The PTC characteristics with reoxidization time at 800℃ have improved about 2~3 orders of magnitude whereas differed according to the sintering temperature. The 0.7 at% Sm-doped (Ba,Ca)TiO₃ samples reveal the best PTC characteristics in the present range of formula and processes.
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.
