Ion Beam Induced Softening of a Nanoelectromechanical Actuator
Abstract
A novel method of engineering the mechanical properties of individual nanostructures is reported. The method of ion irradiation serves as a non-destructive tool to manipulate the spring constant values of isolated nanorods. The slanted Si nanorods were grown by glancing angle deposition (GLAD) technique on a patterned Si(100) substrate with tungsten posts arranged in a 1 micron x 1 micron square pattern. Another Cr nanorods sample were deposited over the Silica balls on Si substrate. The resulting slanted Si nanorods are well separated allowing us to study the mechanical properties of individual nanorods. An atomic force microscope was used in force-distance spectroscopy mode to determine the spring constant value of a single nanorod. The Young's modulus of the Si nanorods undergone remarkable change by 62% after the ion beam irradiation. The sample (at 80K temperature) was irradiated by 100 MeV Ag+8 ions at a fluence of 1014 ions/cm2. The micro-Raman studies over Si nanorods before and after the irradiation show the presence of nanocrystalline regions within the Si nanorods which got amorphized after the irradiation. The ion beam induced enhancement in the amorphization and defects such as vacancies results in the softening of these nanorods. Nanoindentaion studies on the Cr metal nanorods after irradiating with fluence varying from 1012 to 1014 ions/cm2 was performed. The results show a 7 fold enhancement in the hardness value of the Cr nanorods after irradiating with fluence value of 1014 ions/cm2. The results are very encouraging to use ion beam as a modification tool for tailoring the mechanical properties.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 09, 2007
- Accession Number
- ADA473130
Entities
People
- Jitendra Singh
Organizations
- Indian Institutes of Technology