20.3 Outline of Experimental Observations
377
Fig. 20.3 Pressure dependence of the Raman phonon shift for a TPN (Terephthalonitrile) crystal.
Reprinted with permission from [64]
Fig. 20.4 Uniaxial strain softened Raman a G mode and b 2D mode of graphene collected using
polarized light. The G peak splits into the G + and the G − subbands. The strain-induced phonon
softening is approximated using the Grüneisen constants, ∂ω/∂ε. Reprinted with permission from
[65, 66]
Mohiuddin and co-workers [65] suggested that a uniaxial stretching strain can
degenerate the E 2g or the equivalent G optical mode into two components: one is
polarized along the strain and the other is perpendicular to the strain. Increasing
the strain further softens and separates the G
+ and the G
− peaks, in agreement with
first-principles calculations. Small strains also soften the 2D bands but do not split
them.
377
Fig. 20.3 Pressure dependence of the Raman phonon shift for a TPN (Terephthalonitrile) crystal.
Reprinted with permission from [64]
Fig. 20.4 Uniaxial strain softened Raman a G mode and b 2D mode of graphene collected using
polarized light. The G peak splits into the G + and the G − subbands. The strain-induced phonon
softening is approximated using the Grüneisen constants, ∂ω/∂ε. Reprinted with permission from
[65, 66]
Mohiuddin and co-workers [65] suggested that a uniaxial stretching strain can
degenerate the E 2g or the equivalent G optical mode into two components: one is
polarized along the strain and the other is perpendicular to the strain. Increasing
the strain further softens and separates the G
+ and the G
− peaks, in agreement with
first-principles calculations. Small strains also soften the 2D bands but do not split
them.