Preparation of Ni/BaTiO3 Composites and PTC Effect
Ni/BaTiO3 composite was prepared by decomposition of NiC2O4·2H2O/BaTiO3 precursor, which was prepared by precipitating of nickel in the form of oxalate into the BaTiO3 slurry. The composite must be sintered in reducing atmosphere. Otherwise NTC effect would be introduced. The prepared composite almost had no PTC effect. But PTC effect of the Ni/BaTiO3 composite can be effectively renewed by heat-treatment in air. Under a proper composition and method, the composite shows low room-temperature resistivity (ρRT=6.0 Ω·cm) and obvious PTC effect (ρmax/ρmin=102).
Wei Pan, Jianghong Gong, Chang-Chun Ge and Jing-Feng Li
X. L. Li et al., "Preparation of Ni/BaTiO3 Composites and PTC Effect", Key Engineering Materials, Vols. 280-283, pp. 341-344, 2005