High-scan-range cryogenic scanning probe microscope

Abstract

We have designed and constructed a scanning probe microscope operable at temperatures down to 260 mK within a top-loading helium-3 cryostat. It achieves a large scan range with the sample situated near the bottom of the scanning head - maximizing the cooling efficiency of the liquid helium. The scan head is completely thermally compensated, thus eliminating thermal expansion and contraction on cooling and warm-up, as well as thermal drift during operation. We demonstrate the performance using two distinct scanning probe methods: scanning tunneling microscopy and charge accumulation imaging. © 2000 American Institute of Physics.