Effect of gaseous penetration of Pr, Mn into BaTiO₃ ceramics on structure and electrical properties

Pure BaTiO₃ ceramics and Pr, Mn-doped BaTiO₃ ceramics were prepared by a sol-gel method. The pure BaTiO₃ ceramics were modified by the penetration of Pr and Mn in gaseous state, their structure and electrical properties were studied. The results show that the resisitivity of Pr-doped BaTiO₃ ceramics is decreased to 1.01 × 10⁵ Ω·m, the resisitivity of Mn-doped BaTiO₃ ceramics is increased to 1.50 × l0¹³ Ω·m, while both Pr and Mn penetration can decrease the resisitivity of BaTiO₃ ceramics evidently, which is 1.08 × 10³ Ω·m and 1.29 × 10⁵ Ω·m, respectively. The Pr-Mn penetrated BaTiO₃ ceramics show a distinct NTC effect. The XRD results show that the perovskite structure of Pr or Mn doped BaTiO₃ ceramics does not change obviously, but there are new peaks of BaMn_0.12Al_1.88O₄ and Al₈Mn₄Pr in Pr-Mn penetrated BaTiO₃ ceramics. The XPS results show that Pr, Mn and C element are penetrated into BaTiO₃ ceramics, leading to the binding energy of modified BaTiO₃ ceramics increase and their stability improve. The SEM results show that Pr and Mn penetration can improve the surface state of BaTiO₃ ceramics, the grains become finer and grow more integrally than pure BaTiO₃ ceramics, the porosity are decreased visibly.