Applied Physics Letters · 1993 · 70 citations · 4 references
EngineeringShielded RoomMagnetic ResonanceLarge Flux FocusersBiomagnetic MeasurementsMagnetic SensorMagnetismSuperconductivityMagnetohydrodynamicsFirst-order Electronic GradiometerMagnetic Thin FilmsInstrumentationMagnetic MeasurementMagnetic MediumSpintronicsBioelectronicsApplied PhysicsElectrophysiologyMagnetic PropertyMagnetic DeviceMagnetic Field
Low-noise rf SQUID washers fabricated from YBa2Cu3O7 epitaxial thin films have been used to construct a first-order electronic gradiometer operating at 77 K and suitable for biomagnetic measurements. Mechanical adjustment of the two-SQUID gradiometric setup made it possible to attenuate signals due to far magnetic field sources by three orders of magnitude. A magnetic field resolution of ≤280 fT/Hz1/2 above 2 Hz was attained through the use of large flux focusers. The fine structure of human heart magnetocardiograms was recorded in unshielded space. In a shielded room, magnetoencephalograms were obtained. The system was used to obtain new data on auditory evoked cortical response.
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Low-noise YBa2Cu3O7 rf SQUID magnetometer
Yi Zhang, H.-M. Mück, K. Herrmann et al. · Applied Physics Letters · 1992 · 81 citations
Magnetism, Superconducting Material, High-tc Superconductivity +15
YBa2Cu3O7−δ thin-film gradiometers: Fabrication and performance
W. Eidelloth, B. Oh, R. P. Robertazzi et al. · Applied Physics Letters · 1991 · 40 citations