Title :
High temperature circular position sensor based on a giant magnetoresistance nanogranular Agx-Co1-x alloy
Author :
Arana, S. ; Castaño, E. ; Gracia, F.J.
Author_Institution :
Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, Paseo De Manuel Lardizabal, Spain
Abstract :
A new circular position sensor based on giant magnetoresistances (GMR) has been developed. The sensing film is an Ag-Co 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 Nd-Fe-B permanent magnet that provides a sensitivity of 440 μV/V/(°). The operational 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 contact-less way of sensing make this device appropriate for automotive applications. The developed sensor presents excellent characteristics for lifetime since it is not sensitive to pollution; it is frictionless and does not present any type of electrical noise generated by contacts.
Keywords :
boron alloys; cobalt alloys; giant magnetoresistance; high-temperature techniques; iron alloys; magnetic sensors; magnetic thin films; magnetoresistive devices; metallic thin films; nanostructured materials; neodymium alloys; position measurement; silver alloys; 200 C; AgCo; NdFeB; circular Wheatstone bridge configuration; circular position sensor; giant magnetoresistance; magnetic film; nanogranular alloy; nanogranular thin film; permanent magnet; sensing film; Bridge circuits; Contacts; Giant magnetoresistance; Magnetic films; Magnetic sensors; Permanent magnets; Sensor phenomena and characterization; Temperature distribution; Temperature sensors; Transistors;
Conference_Titel :
Sensors, 2003. Proceedings of IEEE
Print_ISBN :
0-7803-8133-5
DOI :
10.1109/ICSENS.2003.1278933
