Non-destructive evaluation of diamond and diamond-like carbon films by laser induced surface acoustic waves

Nanostructuring and Hardness Investigations of Thin Films by Scanning Force Microscopy

“…Very small indentation areas of 5-10 nm length were found with forces of about 1000 nN. Thus preliminary nanohardness values of maximum 40 GPa are obtained which are less than the expected values estimated from Ε modulus and density measurements [11].…”

“…Hardness measurements of DLC films are especially interesting because of the expected high hardness and variety of hardness values in dependence on deposition techniques [11]. Additionally, the DLC films contain a high internal stress and can be grown only to a certain thickness up to 500 nm without additional stress reducing components.…”

Determination of the material properties of polymers using laser-generated broadband ultrasound

“…5 is used. The set-up of the measurement is similar to the ones presented for example by Schneider et al (1997) and Coufal et al (1992). To the authors' knowledge, all previous setups applied transducers based on polymeric piezoelectrics.…”

Acoustic Waves: A Probe for the Elastic Properties of Films

“…The sudden expansion of this line source launches surface waves of limited divergence, propagating along the surface, perpendicularly to the focusing line. The component of the surface displacement normal to the surface itself can be measured, at various distances from the line source, by optical interferometry (Neubrand & Hess, 1992;Withfield et al, 2000), or, in a simpler and more robust way, by a piezoelectric sensor (Lehmann et al, 2002;Schneider et al, 1997Schneider et al, , 1998Schneider et al, , 2000. The recorded displacement is frequency analyzed, yielding the dispersion relation ) ( f v for a frequency interval that can extend over a full frequency decade (e.g.…”

“…The width of the measured frequency interval can allow to to derive the Young modulus and also the film thickness (Schneider et al, 1997(Schneider et al, , 2000. The uncertainties of the results is evaluated numerically by the fitting procedure.…”