Nanomechanical devices constitute an important and growing field, as they allow for new understanding of the mechanical properties at interfaces and surfaces. As an example, a newly developed nanoindentation device has been used to accomplish μN load indents into GaAs. First, it is shown that a plastic zone can be measured and is comparable to theory. Also, it is shown that the rate of indentation affects both the depth and upset zone of low load indents, implying a strain-rate sensitivity effect at room temperature. This is reinforced by observation of what appears to be a glide-based relaxation process.
Bibliographical noteFunding Information:
We would like to thank the Office of Naval Research under Grant No. N00014-89-J-1726, the Center for Interfacial Engineering at the University of Minnesota, under NSF/CDR-8721551, and the Army Research Office under Grant No. DAAL01-94-C-4024 through Hysitron, Inc. for financial support. We would also like to thank Dr. Alex Hsieh at ARL, Watertown, MA for his advice through this SBIR grant.