Nanomechanics of Thin Films
Abstract
The work on the nanomechanics of thin films and microfibriles and interfaces is proceeding in a three-pronged approach, concentrating on deposited films and interfaces. The goal was to examine the structure property relations for mechanical properties in aluminum and aluminum oxide multilayers. Briefly the aluminum films have been deposited in various thicknesses in UHV by evaporation from a W source and subsequently examined by AES, TEM and other surface analyses. For the mechanical data free standing aluminum films were formed by stripping in water from Victawer (R) edge coated thin glass slides following earlier published techniques. Thin aluminum films were deposited at room temperature by physical vapor deposition in ultra-high vacuum for mechanical testing. The film thickness ranged from 20 to 600 nm. Auger electron spectroscopy (AES) showed pure aluminum in the bulk, and a naturally formed layer of amorphous A12O3, with a thickness of 3 to 5 nm, on the surface. Transmission electron spectroscopy (TEM) of these specimens showed the average grain size to vary proportionally with thickness. The samples ranged from 2 to 5 nm in length and 150 um in width. These A1 films, like most deposited films, exhibited brittle behavior when strained uniaxially until fracture. It is also observed that the failure is intergranular. In an attempt to identify the mode of embrittlement, AES was used to investigate impurities at grain boundaries and the fracture edge. (JHD)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1990
- Accession Number
- ADA225180
Entities
Organizations
- Case Western Reserve University