Magnetic Sensors with Picotesla Magnetic Field Sensitivity at Room Temperature
NEBRASKA UNIV LINCOLN DEPT OF PHYSICS AND ASTRONOMY
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High sensitivity magnetic sensors will have a significant impact on security, industry, and quality of life. Many of these applications require sensitivities better than 1 nTHz12 as well as low cost, small size, low maintenance, and low power consumption. This project is to develop highly sensitive magnetic sensors that fit the goal of the MMSON-07-03 Statement of Need. This need is to develop novel sensors applicable to the diverse detection and discrimination problems of munitions and explosives of concern MEC contaminated sites. We present a design of a low power, compact, magnetoresistive sensor. The key features of the design are 1 decreasing the noise by the use of a 64 element bridge, 2 reducing the magnetic noise by annealing of MTJ in high magnetic field and a hydrogen environment, and 3 increasing signal by the use of external low-noise magnetic flux concentrators. The field noise of our prototype magnetic sensor are approximately 1 pTHz12 at 1 kHz, 5 pTHz12 at 10 Hz, and 50 pTHz12 at 1 Hz at room temperature. The magnetic sensor only dissipates 15 mW of power while operating.
- Magnetic and Electric Field Detection and Detectors