Plasma-sprayed thick-film anisotropic magnetoresistive (AMR) sensors

We report our recent work on thick-film permalloy (NiFe) and NiCo-alloy anisotropic magnetoresistive (AMR) sensors made by thermal spray. Various sensor layouts have been fabricated and characterized. The AMR effect of 2.45% and 2.68% is obtained in as-sprayed permalloy and NiCo-alloy sensors. Resistivity of thermal-sprayed thick film is 40-60 /spl mu//spl Omega/ cm, which is higher than bulk material. A maximum /spl Delta/R/R value of 5.2% is achieved after thermal annealing. A high-/spl Delta/R/R value and low-saturation fields are the important features of thermal spray sensors. The very promising results demonstrate the potential applications of thermal spray sensors.