HIGHLY SENSITIVE YBA2CU3O7 DC SQUID MAGNETOMETER WITH THIN-FILM FLUX TRANSFORMER

Citation
D. Grundler et al., HIGHLY SENSITIVE YBA2CU3O7 DC SQUID MAGNETOMETER WITH THIN-FILM FLUX TRANSFORMER, Applied physics letters, 63(19), 1993, pp. 2700-2702
Citations number
14
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00036951
Volume
63
Issue
19
Year of publication
1993
Pages
2700 - 2702
Database
ISI
SICI code
0003-6951(1993)63:19<2700:HSYDSM>2.0.ZU;2-5
Abstract
We have designed and fabricated a thin-film flux transformer by YBa2Cu 3O7/SrTiO3 (YBCO/STO) multilayer process. The flux transformer consist s of a 20-turn input coil of 10 mum linewidth and a single-turn pickup loop surrounding an area of 7.5 by 7.5 mm2. All device levels are pat terned by standard photolithography and Ar-ion-beam etching. The flux transformer has been combined in flip-chip configuration with the squa re washer of a low-noise YBCO dc SQUID. The dc SQUID magnetometer exhi bits a magnetic field sensitivity of 1.4 nT/PHI0. The intrinsic white flux noise level of 70muPHI0/ square-root Hz at 77 K is mainly dominat ed by the SQUID corresponding to a magnetic field resolution of the ma gnetometer of 100 fT/ square-root Hz for frequencies above 40 Hz. At 1 Hz we measured 200 fT/ square-root Hz. Biomagnetic measurements were performed in a magnetically shielded chamber.