Acquisition of a low-voltage Ar ion mill for site-specific and damage-free TEM sample preparation
Abstract
Project Abstract We propose the acquisition of a low-voltage Ar ion mill for site-specific TEM sample preparation. Specifically, the instrument will be utilized for final local polishing of TEM lamellae to remove the amorphous damage layer that is often introduced during focused ion beam (FIB) sectioning. There are numerous research projects on the UC Davis campus, funded by offices of the Department of Defense (DOD), that investigate the structural, mechanical and electrical properties of advanced nanostructured materials. The unique strength of our research programs is based on the combination of materials synthesis, testing of macroscopic properties, and nanoscale characterization under simultaneous application of external stress fields. To accomplish the technical objectives of these programs we use high resolution, aberration-corrected, and in situ transmission electron microscopy techniques to determine the underlying atomic-scale mechanisms of, for instance, plastic deformation, wetting-dewetting transitions, microstructure evolution in bimodal and trimodal aluminum alloys, and electric field assisted formation of grain boundaries. To obtain clean and damage-free samples inert ion beams with energies below 500V are required, which is currently unfeasible for FIB instruments. We therefore propose to acquire an E.A. Fischione NanoMill Model 1040 instrument that will provide capabilities for site-specific broad-beam Ar+ milling at acceleration voltages as small as 50V. Utilization of an inert ion beam avoids alterations of the local chemical compositions while ion induced secondary electron detection enables polishing of specific regions of interest. The availability of the proposed instrument will complement our recently acquired FIB instrument by offering capabilities to minimize or even completely remove any remaining amorphous layers originating from ion beam damage. Existing DOD-funded research efforts on the quantitative atomic scale characterization of nanostructured materials will be supported and strengthened, while new transformative research activities will be enabled. The new capabilities provided by the proposed instrument will be integrated in our undergraduate and graduate education programs in materials science and engineering, and will, therefore, have a direct impact on the training of future scientists and engineers in fields relevant to the DOD mission.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512947
Entities
People
- Klaus van Benthem
Organizations
- Office of Naval Research
- United States Navy
- University of California, Davis