ALPHA-FE2O3 CERAMICS AS NEGATIVE TEMPERATURE-COEFFICIENT THERMISTORS

Authors
CERTO J FURTADO CS FERREIRA AR PERDIGAO JM
Citation
J. Certo et al., ALPHA-FE2O3 CERAMICS AS NEGATIVE TEMPERATURE-COEFFICIENT THERMISTORS, Journal of the European Ceramic Society, 11(5), 1993, pp. 401-405
Citations number
6
Categorie Soggetti
Material Science, Ceramics
Journal title
Journal of the European Ceramic Society → ACNP
ISSN journal
09552219
Volume
11
Issue
5
Year of publication
1993
Pages
401 - 405
Database
ISI
SICI code
0955-2219(1993)11:5<401:ACANTT>2.0.ZU;2-U
Abstract
The electrical behaviour of negative temperature coefficient (NTC) the rmistors can be expressed by the relationship rho = rho25 exp [beta(1/ T - 1/298)]. Good thermistors are thus obtained through the adequate c ontrol of the parameters beta and rho25, which has been achieved in al pha-Fe2O3 ceramics by a convenient processing. Reducing in nitrogen an d then reoxidizing in air has lead to thermisors with good values for beta and reasonable ones for rho25. The samples consisted then of two phases of polycrystalline ceramics, one of hematite the other of magne tite.