Thick-film magnetoresistors and related sensors

This paper deals with ferromagnetic thick-film materials and with sensors relying on the resistance change due to an external magnetic field, usually in the range from 10(4) A m(-1) to 10(5) A m(-1). The research for the development of thick-film magnetoresistors (TF-MRs) is briefly summarized from Ni-based air-fireable pastes to NixCoy-based films fireable in N-2 atmosphere. The different materials are compared, regarding their magnetoresistive performances (mainly in terms of magnetoresistive anisotropy and temperature sensitivity). Some applications are described, covering the area of position sensing (displacement, proximity switch, angle) and the measurement of dynamic quantities (angular rotation) either for digital or analogue control systems.