High-load resistors of doped titanate ceramics showing PTCR-behavior in the entire range of operation

Titelangaben

Moos, Ralf ; Fandel, Marco ; Schäfer, Wolfgang:
High-load resistors of doped titanate ceramics showing PTCR-behavior in the entire range of operation.
In: Journal of the European Ceramic Society. Bd. 19 (1999) Heft 6-7 . - S. 759-763.
ISSN 0955-2219
DOI: https://doi.org/10.1016/S0955-2219(98)00307-0

Volltext

Link zum Volltext (externe URL):

Abstract

Ceramic high-load resistors of donor-doped strontium titanate were manufactured and successfully tested. The samples do not only withstand short high-load pulses (10 ms) with a power loss of ∼1MW, but also show a PTCR behavior in the entire temperature range of operation. Compared to the common BaTiO3-PTCR devices, the samples do not exhibit a grain-boundary controlled resistance, that results in thermo-mechanical stress-induced failure of the devices. The PTCR behavior is a bulk effect, originating from the temperature dependent mobility, that obeys a strong power law. The comparison between thermopower and resistivity measurements has proven to be an excellent method to distinguish between grain boundary-controlled and bulk-controlled resistivity.