Dc-SQUID magnetometers and gradiometers on the basis of quasiplanar ramp-type Josephson junctions

High-transition-temperature superconducting quantum interference devices

“…Several attempts have been made to extend the baseline using single-layer gradiometers in a flip-chip arrangement (Daalmans, 1995;Faley et al, 1997). The concept is illustrated in Figs.…”

Improved reproducible fabrication process of HTS-SQUIDs with ramp-edge Josephson junctions and multilayer structures

“…To achieve further improvement in the devices, an advanced fabrication technology to construct more complicated structures is needed [9]. Faley et al [10] previously demonstrated successful fabrication of HTS-SQUIDs containing ramp-edge JJs.…”

Epitaxial Oxide Heterostructures for Ultimate High-Tc Quantum Interferometers

“…The barrier material and thickness can be chosen for optimum performance in particular applications. The ramp junctions on the chemically etched edges with PBCO films as the barrier and insulation layers have proven parameters that are sufficient for many applications of DC SQUIDs 1997b). The ramp junctions have the advantage that relatively cheap single crystal substrates can be used.…”

“…These requests, in turn, supported the further development of high-T c sensors: more than 20 types of high-T c DC SQUID magnetometers and gradiometers prepared by the high oxygen pressure sputtering technique are now available from Forschungszentrum Jülich GmbH. The epitaxial oxide heterostructures were used in different types of SQUID microscopes ) (Poppe et al, 2004); in a SQUID monitor for measuring the beam current of accelerator radioisotope ions (Watanabe et al, 2004(Watanabe et al, , 2010; for geomagnetic surveys (Chwala et al, 1999, Clem et al, 2001, Fagaly, 2006; for non-contact testing of semiconductor structures with a SQUID laser microscope (Daibo et al, 2002(Daibo et al, , 2005; in the NDE systems for eddy current testing of aircraft wheels and rivets (Grüneklee et al, 1997); for magnetic inspection of prestressed concrete bridges (Krause et al, 2002); for picovoltmeters (Faley et al, 1997b); and for the localization and identification of deep-seated artificial defects such as holes, slots and cracks in multilayer reinforced carbon fibre polymer panels by eddy current SQUID NDE (Valentino et al, 2002) and for magnetocardiography (MCG) measurements (Drung et al, 1995;Faley et al, 2002). Biomagnetic measurements are among those general-purpose applications for which the SQUID measurement systems are preferred due to their sensitivity and ability to measure vector components of magnetic fields.…”