Characteristics of porous BaTiO3-based PTC thermistors fabricated by adding graphite powders

被引:19
作者
Park, K [1 ]
机构
[1] Sejong Univ, Ctr Adv Mat, Dept Adv Mat Engn, Seoul 143747, South Korea
来源
MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY | 2004年 / 107卷 / 01期
关键词
thermistors; electrical properties; BaTiO3; graphite;
D O I
10.1016/j.mseb.2003.10.003
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The crystalline structure, microstructure, and electrical properties of porous graphite-containing BaTiO3-based PTC thermistors were studied. The sintered ceramics showed a tetragonal perovskite structure, irrespective of the added graphite content. The added graphite formed the interstitial solid solutions with Ba0.999Sb0.001TiO3 and was distributed homogeneously in the sintered ceramics. The grain size of the as-sintered graphite-containing BaTiO3-based ceramics was much larger than that of the as-sintered graphite-free ones. This is mainly due to the exothermic reactions of the graphites and oxygen molecules in the ceramics. The porosity of the as-sintered ceramics increased with increasing graphite content due to an enhanced evolution of CO and CO2 gases associated with the exothermic reactions. It was found that the newly prepared porous graphite-containing BaTiO3-based PTC thermistors showed a large PTCR effect. (C) 2003 Ellsevier B.V. All rights reserved.
引用
收藏
页码:19 / 26
页数:8
相关论文
共 37 条
[1]   THE EFFECT OF MN ON THE POSITIVE TEMPERATURE-COEFFICIENT OF RESISTANCE CHARACTERISTICS OF DONOR DOPED BATIO3 CERAMICS [J].
ALALLAK, HM ;
BRINKMAN, AW ;
RUSSELL, GJ ;
WOODS, J .
JOURNAL OF APPLIED PHYSICS, 1988, 63 (09) :4530-4535
[2]   EFFECTS OF ALUMINUM ON THE ELECTRICAL AND MECHANICAL-PROPERTIES OF PTCR BATIO3 CERAMICS AS A FUNCTION OF THE SINTERING TEMPERATURE .1. ELECTRICAL BEHAVIOR [J].
ALALLAK, HM ;
PARRY, TV ;
RUSSELL, GJ ;
WOODS, J .
JOURNAL OF MATERIALS SCIENCE, 1988, 23 (03) :1083-1089
[3]   Effect of humidity on the electrical response of porous BaTiO3 ceramics [J].
Caballero, AC ;
Villegas, M ;
Fernández, JF ;
Viviani, M ;
Buscaglia, MT ;
Leoni, M .
JOURNAL OF MATERIALS SCIENCE LETTERS, 1999, 18 (16) :1297-1299
[4]   EFFECT OF SINTERING AIDS ON MICROSTRUCTURES AND PTCR CHARACTERISTICS OF (SR0.2BA0.8)TIO3 CERAMICS [J].
CHENG, HF ;
LIN, TF ;
HU, CT ;
LIN, IN .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1993, 76 (04) :827-832
[5]  
EMOTO H, 1992, NIPPON SERAM KYO GAK, V100, P555, DOI 10.2109/jcersj.100.555
[6]   Degradation behavior of PTCR BaTiO3 in reducing gases [J].
Er, G ;
Takeuchi, N ;
Ishida, S ;
Hosokawa, K ;
Yamazaki, K ;
Kitoh, N ;
Namikawa, Y ;
Niimi, H .
JOURNAL OF THE CERAMIC SOCIETY OF JAPAN, 1996, 104 (12) :1091-1096
[7]   EFFECTS OF PORE MORPHOLOGY AND GRAIN-SIZE ON THE DIELECTRIC-PROPERTIES AND TETRAGONAL CUBIC PHASE-TRANSITION OF HIGH-PURITY BARIUM-TITANATE [J].
FANG, TT ;
HSIEH, HL ;
SHIAU, FS .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1993, 76 (05) :1205-1211
[8]  
Gaskell D.R., 1995, INTRO THERMODYNAMICS, P547
[9]   Grain orientation dependence of the PTCR effect in niobium-doped barium titanate [J].
Hayashi, K ;
Yamamoto, T ;
Sakuma, T .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1996, 79 (06) :1669-1672
[10]   RESISTIVITY ANOMALY IN DOPED BARIUM TITANATE [J].
HEYWANG, W .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1964, 47 (10) :484-490