A new circular position sensor based on giant mag- netoresistances has been developed. The sensing film is an AgCo nanogranular thin film patterned in a circular Wheatstone bridge configuration. This alloy shows a high magnetoresistance (8%) at room temperature within the field generated by an NdFeB perma- nent magnet that provides a sensitivity of 440 V V. The op- erational temperature range of this sensor is 40 C 120 C, although the magnetic film tolerates higher temperatures up to 200 C. These parameters and the contactlessless way of sensing make this device appropriate for automotive applications. The de- veloped sensor presents excellent characteristics for life, since it is not sensitive to pollution; it is frictionless and does not present any type of electrical noise generated by contacts. Index Terms—AgCo alloy, giant magnetoresistances (GMR), magnetoresistance, position sensor.
[1]
F. J. Gracia,et al.
Magnetic position sensor based on nanocrystalline colossal magnetoresistances
,
2001
.
[2]
Xiong,et al.
Investigation of giant magnetoresistance in magnetic, concentrated, nanostructured alloys.
,
1993,
Physical Review B (Condensed Matter).
[3]
Gotthard Rieger,et al.
GMR sensors for contactless position detection
,
2001
.
[4]
J. Barnard,et al.
‘Giant’ magnetoresistance observed in single layer Co-Ag alloy films
,
1992
.
[5]
F. J. Gracia,et al.
Room temperature colossal magnetoresistance in nanocrystalline La0.67Sr0.33MnO3 sputtered thin films
,
2000
.