Raman spectroscopy of ZnO in a diamond anvil cell

Abstract

This is a report on the instrumentation we developed for the Raman spectroscopy of ZnO microribbon inside the diamond anvil cell. This describes the basic configuration of the Raman spectrometer and the limitations of the current configuration. Two types of pressure media were investigated – silicone oil and NaCl. Two objective lenses of different numerical apertures were considered. Spectra from silicone oil strongly disturbs the characteristic spectra of ZnO. NaCl has no peaks at the strongest Raman shifts of ZnO, but it was found that diamond further suppresses the ZnO shifts through the tail of the Raman shift near 1333 cm^–1. Detection of ZnO's E₂^high mode was difficult but improved with the use of higher numerical aperture objective. To collect strong ZnO characteristic intensities from inside the cell, a confocal Raman system is suggested.