Paper Title:
Silica Additions and the Performance of PTC Thermistors
  Abstract

A series of PTC thermistors, based on BaTiO3, doped with Ca, Mn and Y, were prepared with additions of SiO2 at levels of 0, 1, 2 and 3 at. %. The effect of the SiO2 additions and cooling rate on microstructural development and bulk performance were characterised using a combination of SEM, EBSD, and R-T experiments. It was found that the addition of SiO2 increased grain size marginally, and decreased sample density by reducing the amount of grain-grain contact. The addition of SiO2 also modified the distribution of grain boundary types by systematically decreasing the proportion of low-Σ grain boundaries within the microstructure. Electrical behaviour was modified by adding SiO2 or increasing the sample cooling rates; in both cases there was an increase in ρ25 and a decrease in ρmax, with ρmax also being displaced to higher temperatures.

  Info
Periodical
Edited by
P. VINCENZINI
Pages
2362-2370
DOI
10.4028/www.scientific.net/AST.45.2362
Citation
C. Leach, M. Zubair, R. Freer, "Silica Additions and the Performance of PTC Thermistors", Advances in Science and Technology, Vol. 45, pp. 2362-2370, 2006
Online since
October 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Cheng Ju Zhang, Jin Feng Wang, Wen Bin Su, Guo Zhong Zang, Hong Cun Chen
Abstract:The effects of Pr on the microstructure and nonlinear electrical properties of the (Co,Ta)-doped SnO2 varistors were investigated. It was...
275
Authors: Yoshiaki Kinemuchi, Hisashi Kaga, Satoshi Tanaka, Keizo Uematsu, Hiromi Nakano, Koji Watari
Abstract:Thermoelectric properties of zinc oxide ceramics are largely influenced by the mobility variation because of the formation of double...
581
Authors: Dan Liu, Yong Ke Yan, He Ping Zhou
Abstract:<001> textured 0.675Pb(Mg1/3Nb2/3)O3-0.325PbTiO3 (PMN-32.5PT) ceramics were prepared by templated grain growth with micron scale BaTiO3...
15
Authors: Jin Liang He, Jun Hu, Feng Chao Luo
Abstract:The presence of twins in ZnO varistors raises interesting questions concerning the potential role of those electrically distinctive twin...
490
Authors: Adriana Scoton Antonio Chinelatto, Milena Kowalczuk Manosso, Elíria Maria Jesus Agnollon Pallone, Ana Maria Souza, Adilson Luiz Chinelatto
Abstract:Sintering in two-steps has been applied with success for densification of nanometric and submicrometer ceramic powders without grain growth....
221