We report the instrumentation and experimental results of a cryogenic scanning microwave impedance microscope. The microwave probe and the scanning stage are located inside the variable temperature insert of a helium cryostat. Microwave signals in the distance modulation mode are used for monitoring the tip-sample distance and adjusting the phase of the two output channels. The ability to spatially resolve the metal-insulator transition in a doped silicon sample is demonstrated. The data agree with a semiquantitative finite element simulation. Effects of the thermal energy and electric fields on local charge carriers can be seen in the images taken at different temperatures and dc biases. © 2011 American Institute of Physics.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-F1-033-02
Acknowledgements: This research is funded by Center of Probing the Nanoscale (CPN), Stanford University, National Science Foundation (NSF) Gran No. DMR-0906027, and (U.S.) Department of Energy (DOE) Contract No. DE-FG03-01ER45929-A011 for low temperature cryostat. This publication is also based on work supported by Award No. KUS-F1-033-02, made by King Abdullah University of Science and Technology (KAUST) under the global research partnership (GRP) program. CPN is an NSF NSEC,National Science Foundation (NSF) Grant No. PHY-0425897.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.