Scanning probe microscope for use in fluids

Abstract

A microscope suitable for use in atomic force microscopy and scanning tunneling microscopy includes an electrochemical liquid cell. Vertically adjustable supporting mounts extend downwardly from a frame and include magnetic balls to which a sample platform may be attached. At least two adjustment pegs extend downwards from the frame and engage the platform for horizontal adjustment at apertures therethrough. The pegs may be moved out of engagement with the platform to reduce drift. An electrical sensor provides a signal to indicate whether the pegs are in contact with the platform. A bore in the frame is provided through which the chosen scanning head may be inserted so as to engage a sample on the platform. A hermetically sealed chamber may be formed around the sample by a seal between the scanner of the microscope and the frame as well as an enclosure which fits over the bottom of the microscope and engages the frame at an O-ring seal. Scanning heads may be rotated for adjustment. The fluid cell is attached to the sample platform with adjustable magnetic clamps. The cell is easily placed over the sample with no need of separate clamps or screws. Electrochemical control of the potential of either or both of the sample and the force sensing probe is used so as to control interactions between the probe and the sample surface. Contamination of the surface being studied may be controlled by placing the scanning probe and the surface under a protective fluid.