High-Tc directly coupled direct current SQUID gradiometer with flip-chip flux transformer

被引：28

作者：

Tian, YJ ^{[1
]}

Linzen, S ^{[1
]}

Schmidl, F ^{[1
]}

Dörrer, L ^{[1
]}

Weidl, R ^{[1
]}

Seidel, P ^{[1
]}

机构：

[1] Univ Jena, Inst Festkorperphys, D-07743 Jena, Germany

来源：

APPLIED PHYSICS LETTERS | 1999年 / 74卷 / 09期

关键词：

D O I：

10.1063/1.123531

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We have designed and fabricated a flip-chip-type gradiometer as a sensor for measurement of weak magnetic signals. The gradiometer consists of a directly coupled direct current superconducting quantum interference device (SQUID) gradiometer coupled to a flux transformer made from a YBa2Cu3O7*/YBa2Cu3O7/CeO2/YSZ multilayer on 2 in. Si wafer, where YBa2Cu3O7*(YBCO*) is a nonsuperconducting crystalline film. The coupling coefficient of 0.18 is obtained for the flip-chip gradiometer. The transformer increases effectively the resolutions of the gradiometer. We obtain a magnetic field gradient resolution of 73 fT cm(-1) Hz(-1/2) in the white region, and 596 fT cm(-1) Hz(-1/2) at 1 Hz. The magnetocardiograms were successfully measured at a distance of nearly 100 mm from the gradiometer center to the human heart in a shielded room. (C) 1999 American Institute of Physics. [S0003-6951(99)00509-4].

引用

页码：1302 / 1304

页数：3

共 9 条

[1] Single-layer and integrated YBCO gradiometer coupled SQUIDs [J].