Raman measurements
were carried out
using a Horiba T6400 instrument in a single spectrometer configuration
with an 1800 L/mm grating and a Si charge-coupled device cooled by
liquid nitrogen. The laser excitation, operated at 532 nm wavelength
and 6 mW power to avoid heat-induced degradation of the sample, was
focused onto the specimen using a 100×/0.9 NA objective, which
was also used to collect the Raman signal in the so-called backscattering
geometry.
were carried out
using a Horiba T6400 instrument in a single spectrometer configuration
with an 1800 L/mm grating and a Si charge-coupled device cooled by
liquid nitrogen. The laser excitation, operated at 532 nm wavelength
and 6 mW power to avoid heat-induced degradation of the sample, was
focused onto the specimen using a 100×/0.9 NA objective, which
was also used to collect the Raman signal in the so-called backscattering
geometry.