High-frequency magnetic microscopy using a high-T/sub c/ SQUID

We have used a liquid-nitrogen-cooled scanning SQUID microscope to obtain magnetic images at frequencies ranging from zero to 200 GHz, that is, from audio frequencies through the radio frequency band and into the millimeter microwave band. We present images of thin film and bulk metallic samples, with a spatial resolution of about 30 /spl mu/m, taken using various readout schemes we have developed.<
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