1. Scanning SQUID Microscopy for Sensing Vector Magnetic Field
- Author
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The Dang Vu, Masaki Toji, Atsuki Ito, Shigeyuki Miyajima, Thanh Huy Ho, Hiroaki Shishido, Masaaki Maezawa, Mutsuo Hidaka, Masahiko Hayashi, and Takekazu Ishida
- Subjects
010302 applied physics ,Squid ,Microscope ,Materials science ,biology ,business.industry ,Cryocooler ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,Magnetic field ,Optics ,law ,Scanning SQUID microscopy ,Electromagnetic coil ,biology.animal ,0103 physical sciences ,Electrical and Electronic Engineering ,business ,010301 acoustics ,Image resolution ,Voltage - Abstract
We report a vector-scanning SQUID microscope for probing a vector magnetic field. We designed and fabricated a vector [three-dimensional (3-D)] SQUID sensor with the aid of Nb multilayer fabrication technology. Our vector SQUID sensor on a single chip is composed of a vector sensor with three orthogonal pick-up coils, which catch the X , Y, and Z magnetic field components. We improved both the sensitivity and the spatial resolution not only by reducing the inner diameter but also by increasing the number of pick-up-coil windings within the framework of the multilayer technique. Our SQUID sensors operated properly, and the characteristics showed a good agreement with our design parameters. Since the sensor is suitable for our SQUID microscope, we are constructing our scanning microscope platform by using a Gifford-McMahon cryocooler for allowing long-time measurements. We also succeeded in connecting our vector SQUID sensor to a commercial flux-locked loop readout circuit (Magnicon Inc., Model XXF-1) to generate the voltage outputs, which are proportional to the XYZ components of the external magnetic field. We also use an XYZ piezo-driven scanner for the precise control of the pick-up-coil positions over the 3-D range of 5 × 5 × 5 mm 3 with a step size of 10 nm at 4 K. more...
- Published
- 2018
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