Design and performance of a highly sensitive magnetoresistive sensor using high Tc YBa/sub 2/Cu/sub 3/O/sub 7-x/ ceramic superconducting film

This paper reports on the design and development of a magnetoresistive sensor using a high Tc ceramic superconducting film. We have fabricated a meander-shape element by the selective growth of an electrophoretic Ag/sub 2/O-doped YBa/sub 2/Cu/sub 3/O/sub 7-x/ film. The doping amount of Ag/sub 2/O has been optimized to improve the magnetic field sensitivity and the element has been coupled to a Permalloy to enhance the sensitivity. A magnetic field resolution of 8.5 pT Hz/sup -1/2/ at 100 Hz at 77 K has been obtained with no input coil. To demonstrate this high sensitivity, we have been successful in measuring a human magnetocardiogram.<
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