The Influence of Donor-Doped Content on PTC Effect of Ba-Excess BaTiO₃ Based Ceramics Fired in Reducing Atmosphere

Abstract:

We investigated the influence of the Sm-doped contentration on the electrical properties and PTC effect of Ba-excess BaTiO₃ Based Ceramics, which were fired at 1300 °C for 30 min in a reducing atmosphere and then reoxidized at 850 °C for 1 h. The results showed that the donor dopant affected PTC characteristics and the electrical properties of the BSMT ceramics, whose room temperature resistivity first decreased and then increased with an increase in the Sm³⁺-doped content across the range from 0.1 to 0.5 mol%. The BSMT specimens exhibited a remarkable PTC effect, with a resistance jump greater by 2.7 orders of magnitude, along with a low room temperature resistivity of 128.6 Ω∙cm at the donor-doped content of 0.3 mol%. The influence of the donor dopant on the grain size of the as-fired samples has been also investigated.

• Periodical: Advanced Materials Research (Volume 1015)
• Pages: 425-429
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1015.425
• Online since: August 2014
• Authors: Xu Xin Cheng*, Hai Ning Cui, Dong Xiang Zhou, Qiu Yun Fu
• Keywords: Ba-Excess, BaTiO₃, Ceramic, Donor-Dopant, PTC Effect

References

[1] Y.K. Chung and S.C. Choi. Effects of the re-oxidation temperature and time on the PTC properties of Sm-doped BaTiO3 [J]. J. Korean Chem. Soc. 2009 46(3) 330–335.

[2] Z.C. Lia, H. Zhang, X.D. Zou. Bill Bergman, Synthesis of Sm-doped BaTiO3 ceramics and characterization of a secondary phase [J]. Mater. Sci. Eng., B, 2005 116 35–39.

[3] M.W. Mancini and P.I. Paulin Filho. Direct observation of potential barriers in semiconducting barium titanate by electric force microscopy [J]. J. Appl. Phys., 2006 100 104501.

DOI: 10.1063/1.2382454

[4] W. Heywang. Resistance anomaly in doped barium titanate [J]. J. Am. Ceram. Soc, 1964 47(10) 484.

[5] G.H. Jonker. Some aspects of semiconducting barium titanate [J]. Solid-State Electron, 1964 7 903.

DOI: 10.1016/0038-1101(64)90068-1

[6] J. Illingsworth and so on. Woods. The influence of Mn on the grain-boundary potential barrier characteristics of donor-doped BaTi03 ceramics [J]. J. Appl. Phys., 1990 67 (4) (2088).

DOI: 10.1063/1.345567

[7] W. Heywang. Barium titanate as a semiconductor with blocking layers [J]. Solid-State Electron, 1961 3 51.

[8] X.X. Cheng, D.X. Zhou, Q.Y. Fu, S.P. Gong, D.C. Zhao. Influence of sintering conditions on the electrical properties and the PTC effect of the multilayer Ba1. 005(Ti1-xNbx)O3 ceramics with Ni internal electrode, Journal of Materials Science: Materials in Electronics [J]. 2012 23(12), 2202-2209.

DOI: 10.1007/s10854-012-0753-2

[9] X.X. Cheng and so on. Effect of reoxidation annealing on the PTC behavior of multilayer Nb5+-doped BaTiO3 ceramics with Ni internal electrode [J]. J. Phys. D: Appl. Phys., 2012 45(38) 385306 (7pp).

DOI: 10.1088/0022-3727/45/38/385306

[10] H. Niimi, K. Mihara and Y. Sakabe. Influence of Ba/Ti Ratio on the Positive Temperature Coefficient of Resistivity Characteristics of Ca-Doped Semiconducting BaTiO3 Fired in Reducing Atmosphere and Reoxidized in Air [J]. J. Am. Ceram. Soc., 2007 90(6) 1817-1821.

DOI: 10.1111/j.1551-2916.2007.01701.x

[11] H. Niimi and so on. Effects of Ba/Ti Ratio on Positive Temperature Coefficient of Resistivity Characteristics of Donor-doped BaTiO3 Fired in Reducing Atmosphere [J]. Jpn. J. Appl. Phys. 2007 46(2) 675-680.

DOI: 10.1143/jjap.46.675

[12] X.X. Cheng, D.X. Zhou, Q.Y. Fu. PTC Effect of Chip Type Ba1. 005-xSmxTiO3 Ceramics prepared by Reduction Sintering-Reoxidation Method, Trans. Ind. Ceram. Soc., 2012 71(4) 100-105.