Raman spectroscopic characterization of CH sub(4) density over a wide range of temperature and pressure

The positions of the CH sub(4) Raman nu sub(1) symmetric stretching bands were measured in a wide range of temperature (from -180 degree C to 350 degree C) and density (up to 0.45g/cm super(3)) using high-pressure optical cell and fused silica capillary capsule. The results show that the Raman band shift is a function of both methane density and temperature; the band shifts to lower wavenumbers as the density increases and the temperature decreases. An equation representing the observed relationship among the CH sub(4) nu sub(1) band position, temperature, and density can be used to calculate the density in natural or synthetic CH sub(4)-bearing inclusions. Copyright copyright 2014 John Wiley & Sons, Ltd. Raman spectra of CH sub(4) were collected over a wide range of temperature and pressure. The results show that the CH sub(4) nu sub(1) band shift is a function of both methane density and temperature; the band shifts to lower wavenumbers as the density increases and the temperature decreases.