Scanning Tunneling Microscope for UHV to High Pressure and High Temperature Operation

APPLICATIONS OF TECHNOLOGY:

Manufacture of scanning tunneling microscopes for

evaluating catalysis reactions and processes
other surface science research

ADVANTAGES:

Operates at pressures from ultrahigh vacuum (UHV) to ~10 bars
Operates at higher temperatures (up to ~450°K) than conventional STM
Convenient transfer/change out of catalyst samples and STM tip

ABSTRACT:

Scientists at Berkeley Lab have invented a scanning tunneling microscope (STM) capable of operating under a large range of pressures and at high temperatures. Its ability to operate at pressure and temperature conditions similar to those of industrial gas-solid heterogeneous catalysis makes it particularly well suited for in situ study of catalyst surface structures. This marks a significant improvement in microscopy compared to conventional STMs operating under zero or vacuum pressure only.

In the Berkeley Lab microscope, the STM head is installed inside a specially designed, low volume reactor that can remain at high pressure. The reactor is suspended within an UHV chamber to give users the ability to study reactions at the wide range of pressures and temperatures noted. Vibration separation of the reactor from the rest of the system facilitates high resolution images of sample surfaces. The design also incorporates a convenient sample exchange and STM tip replacement system.

The STM microscope system has performed reliably through extensive STM studies by the inventors’ workgroup. Previously unobserved surface structures and catalysis phenomena have been revealed using this novel tool.

STATUS: Patent pending. Available for licensing or collaborative research.

DEVELOPMENT STAGE: Fully operational prototype.

FOR MORE INFORMATION:

F. Tao, D. Tang, M. Salmeron, G. A. Somorjai. “A new scanning tunneling microscope reactor used for high-pressure and high-temperature catalysis studies,” Review of Scientific Instruments, 79 (8), 084101: 1-6 (2008).

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

Dedicated Test Surface for Calibration of High Performance Optical Systems, IB-2499

Non-contact Nanoscale Imaging of Liquids and Weakly Bound Materials, IB-1047

Transmission Electron Microscope Phase-contrast Enhancement, IB-2036

Graphene Membranes for Nanometer-scale Lithography and Single Atom Resolution TEM Imaging, IB-2501

REFERENCE NUMBER: IB-2735