We use micro-Raman spectroscopy to study strain in free-standing graphene monolayers anchored to SiN holes of non-circular geometry. We show that a uniform differential pressure load yields measurable deviations from hydrostatic strain, conventionally observed in radially symmetric microbubbles. A pressure load of 1 bar yields a top hydrostatic strain of ? 0.7% and a G± splitting of 10 cm-1 in graphene clamped to elliptical boundaries with axes 40 and 20 ?m, in good agreement with the calculated anisotropy ?? ? 0.6% and consistently with recent reports on Grüneisen parameters. The implementation of arbitrary strain configurations by designing suitable boundary clamping conditions is discussed.
Anisotropic straining of graphene using micropatterned SiN membranes
Colangelo F;Pitanti A;Colle R;Grosso G;Tredicucci A;Roddaro S
2016
Abstract
We use micro-Raman spectroscopy to study strain in free-standing graphene monolayers anchored to SiN holes of non-circular geometry. We show that a uniform differential pressure load yields measurable deviations from hydrostatic strain, conventionally observed in radially symmetric microbubbles. A pressure load of 1 bar yields a top hydrostatic strain of ? 0.7% and a G± splitting of 10 cm-1 in graphene clamped to elliptical boundaries with axes 40 and 20 ?m, in good agreement with the calculated anisotropy ?? ? 0.6% and consistently with recent reports on Grüneisen parameters. The implementation of arbitrary strain configurations by designing suitable boundary clamping conditions is discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
