2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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TechConnect Summit
Clean Technology 2008

Maintaining Clean Surfaces in Cryogenic Measurement Environments

J. Lindemuth
Lake Shore Cryogenics, US

Keywords:
cryogenic measurements, vacuum surfaces, cryo-pumping

Abstract:
Surfaces of nanoscale materials of all types must be kept clean to properly characterize their behavior. Materials that are characterized at cryogenic temperatures and in vacuum present additional challenges to maintaining clean surfaces. Any residual contaminants will cryo-pump onto the cold surface of the system, including the sample [1]. We describe a method of independent cooling of the cryostat and the sample. In this method the sample is kept at an elevated temperature, driving off condensates on the surface, while the cryostat is cooled to base temperature. All contaminants in the vacuum are cryo-pumped onto the cold surfaces. These surfaces are maintained at the lowest temperature possible. At this point the sample is cooled to base temperature. Analysis, including residual gas analysis, of the vacuum and surface shows that the condensations on the surface of the sample are reduced to a minimal level. 1. Cryogenic scanning Hall-probe microscope with centimeter scan range and submicron resolution Rafael B. Dinner, M. R. Beasley, and Kathryn A. Moler, Rev. Sci. Instrum. 76, 103702 (2005)


Nanotech 2008 Conference Program Abstract