We have investigated how ambient humidity can affect quantitative measurements of elastic properties on the nanoscale. Using an emerging technique called atomic force acoustic microscopy (AFAM), two samples were examined: a thin film of fluorosilicate glass (FSG) and a section of borosilicate glass. When experimental results were analyzed using a simple model of the AFM is believed to be due to the presence of a humidity-dependent layer of water on the sample. To account for this, the data analysis model was extended to include ciscoelastic damping between the tip and the sample. A damping term proportional to the relative identation modulus M from k* yielded similar values regardless of measurement humidity. These results indicate that environment conditions can influence quantitative nanoscale measurements of elastic properties, at least in some materials.
Citation: Journal of Applied Physics
Pub Type: Journals
AFAM, elastic properties, relative humidity, ultrasonics