| 摘要 |
A metrology device optically measures the electrical conductivity of a magnetic sample, such as a Tunneling Magnetoresistance (TMR) or Giant-Magneto Resistance (GMR) device, using Time Domain Thermo Reflectance (TDTR) to measure a cooling curve for the sample while a magnetic field is applied to the sample. The thermal conductivity of the sample may be determined using the cooling curve and the variation of the cooling curve with varying applied magnetic fields is measured. The electrical conductivity is determined for the sample in the magnetic field based on the thermal conductivity. If desired, single reflectance changes may be measured at a particular delay after heating, and the reflectance change at this delay may be used to determine the electrical conductivity. Of particular interest is the amount of change in electric conductivity for a given applied magnetic field because this yields a measure of the sensitivity of the sensor.
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