Scanning Probe Microscopy
Digital Instruments Nanoscope IIIa Dimension 3100 Scanning Probe Microscopy (SPM) Facility provides nanometer-scale characterization of materials by using Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM), and Magnetic Force Microscopy (MFM).
AFM image of monodispersed, sub-10nm Fe clusters produced by inert gas condensation.
Facility specialist Dr. Lanping Yue
STM measures a weak electrical current between a wire or metal-coated silicon tip and the sample surface. The STM technique allows one to image atomic structure on electrically conductive surfaces. AFM measures the interaction force between the tip and surface. AFM has been used for characterization of the surface topography of a sample. It can provide three-dimensional images and quantitative data analysis (such as roughness, grain size, and cross-section plots). MFM measures change of the interaction force between a magnetized probe and the local stray magnetic field from the sample. Our MFM facility can scan samples in external magnetic fields, which is useful for magnetic domain imaging. The fields available using permanent magnets are -0.25 T to 0.25 T perpendicular to the sample and -0.45 T to 0.45 T parallel to the sample. The resolution of our MFM tips modified by Focused-Ion-Beam (FIB) milling is around 15 nm, which is currently state-of-the-art capability.
| MFM and AFM images of nanoscale FePt magnetic array generated by template-mediated self-assembly. |
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The facility is available to all qualified researchers, who are properly trained at UNL, on payment of the appropriate charges for equipment use. Research collaborations are welcome from all UNL faculty as well as companies in Nebraska and elsewhere.
Professor Sy-Hwang Liou, Faculty
Supervisor
Dr. Lanping Yue, Specialist
Location: 16 Ferguson Hall
University of Nebraska
Lincoln, NE 68588-0111
phone: (402) 472-2742
fax: (402) 472-2879
e-mail: lyue2@unl.edu
website: http://ncmn-webcal.unl.edu/spm/
