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| Ultra Low Field Sensor Using GMI Effect in NiFe/Cu Wires |
| Journal of Magnetics, Volume 12, Number 1, 31 Mar 2007, Pages 35-39 |
Pratap Kollu(Department of Materials Science and Engineering and ReCAMM, Chungnam National University), Doung-Young Kim(Department of Materials Science and Engineering and ReCAMM, Chungnam National University), Cheol-Gi Kim*  (Department of Materials Science and Engineering and ReCAMM, Chungnam National University) |
| Abstract |
| A highly sensitive magnetic sensor using the Giant MagnetoImpedance effect has been developed. The sensor performance is studied and estimated. The sensor circuitry consists of a square wave generator (driving source), a sensing element in a form of composite wire of a 25 µm copper core electrodeposited with a thin layer of soft magnetic material (Ni80FE20), and two amplifier stages for improving the gain, switching mechanism, scaler circuit, an AC power source driving the permeability of the magnetic coating layer of the sensing element into a dynamic state, and a signal pickup LC circuit formed by a pickup coil and an capacitor. Experimental studies on sensor have been carried out to investigate the key parameters in relation to the sensor sensitivity and resolution. The results showed that for high sensitivity and resolution, the frequency and magnitude of the ac driving current through the sensing element each has an optimum value, the resonance frequency of the signal pickup LC circuit should be equal to or twice as the driving frequency on the sensing element, and the anisotropy of the magnetic coating layer of the sensing wire element should be longitudinal. |
| Keywords: CDMPI sensor; GMI; magnetometer; microwires |
| DOI: 10.4283/JMAG.2007.12.1.35 |
| Full Text: PDF |
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