Low-noise YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} single layer dc superconducting quantum interference device (SQUID) magnetometer based on bicrystal junctions with 30{degree} misorientation angle

Journal Article · Thu Jan 01 04:00:00 EST 1998 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.120685· OSTI ID:565593

Beyer, J; Drung, D; Ludwig, F ^[1]; Minotani, T; Enpuku, K ^[2]

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1. Physikalisch-Technische Bundesanstalt, Institut Berlin, Abbestr, 2-12, D-10587 Berlin (Germany)
2. Department of Electronic Device Engineering, Kyushu University, Fukuoka 812 (Japan)

We have fabricated and characterized a low-noise direct-coupled magnetometer based on a 100 pH YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} dc superconducting quantum interference device (SQUID) on a 10 mm{times}10 mm SrTiO{sub 3} bicrystal substrate with 30{degree} misorientation angle. The thin films were deposited by hollow cathode discharge sputtering and patterned using conventional photolithography and Ar ion beam etching. The SQUID magnetometer was operated using direct-coupled flux-locked-loop electronics with bias reversal. The sensor had a usable voltage swing of 39 {mu}V and a white magnetic field noise of 32 fTHz{sup {minus}1/2} with a 1/f corner at 2 Hz, including electronics and environmental noise. The voltage versus flux (V{minus}{Phi}) characteristic showed a pronounced distortion on the negative slope. Numerical simulations were performed to explain the distorted V{minus}{Phi} characteristic. Measurements of magnetocardiograms demonstrate the suitability of this sensor for biomagnetic applications. {copyright} {ital 1998 American Institute of Physics.}

• OSTI ID: 565593
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 2 Vol. 72; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM COMPOUNDS
BARIUM OXIDES
BICRYSTALS
COPPER OXIDES
ETCHING
HIGH-TC SUPERCONDUCTORS
MAGNETOMETERS
NOISE
SIMULATION
SQUID DEVICES
YTTRIUM COMPOUNDS
YTTRIUM OXIDES