High-T/sub c/ SQUID microscope for room temperature samples

Abstract

A high-T/sub c/ SQUID microscope has been constructed for imaging samples at room temperature and atmospheric pressure. The SQUID is mounted on the upper end of a sapphire rod, cooled to liquid nitrogen temperature, below a 3-/spl mu/m thick silicon nitride vacuum window. This arrangement yields a SQUID-to-sample separation as low as 15 /spl mu/m. A sample can be placed on the window or scanned over the SQUID to produce magnetic images.