Elastic Modulus Measurements on Large Diameter Nanowires Using a Nano-Assembled Platform

This paper presents atomic force spectroscopy (AFM) results from large diameter nanowires (NWs), which range in radius from 150 nm to 300 nm, within a nano-assembled platform. The nanomechanical platform is constructed by assembling single NWs across pairs of gold nano-electrodes using dielectrophoresis and contains a short, suspended segment of the NW (in air) between the assembly electrodes. Atomic force microscope (AFM) force spectroscopy measurements are obtained by indenting the NW within this suspended segment and result in deformation of the NW involving a combination of both, bending and nano-indentation modes. This paper demonstrates the measurement technique using lithium iron phosphate NWs as a model system and presents a finite element model to extract the Young's modulus from nanomechanical data. The estimated Young's modulus of this material, which is an electrode material system of interest for next-generation lithium-ion batteries, was found to be diameter dependent and was observed to range in values between 100 MPa and 575 MPa.