Compensation Point Temperature Sensor
Original Publication Date: 1978-Feb-01
Included in the Prior Art Database: 2005-Feb-20
Amorphous ferrimagnetic rare earth-transition metal alloys produce a large anomalous hall voltage in the order of a few millivolts that abruptly changes sign at the compensation point at which magnetization of the rare earth and transition metal sublattices cancel. Adjustment of film stoichiometry determines a unique temperature at which compensation occurs. The compensation point Hall effect, unique to this class of materials, is useful as a solid state on-off temperature sensor. With a Gd-Co binary alloy it is possible to adjust the compensation point from -250 to +250 degrees C with a +/-5 degree C accuracy. The device can be mass produced economically by vacuum evaporation onto a plastic substrate.