The Fluorescence of Diamond and Raman Spectroscopy at High Pressures Using a New Design of Diamond Anvil Cell

Abstract

A new design of diamond anvil high pressure cell suitable for use in infrared and Raman spectroscopy is described. Its performance is demonstrated with particular reference to the pressure dependence of the infrared spectrum of K₂PtCl₆ and the Raman spectrum of W(CO)₆. In contrast to earlier reports, in which forward scattering geometry was used, this design of cell is shown to be very suitable for Raman use in the 180° excitation mode. However, severe limitations are imposed by the fluorescence emission of diamond and of sapphire. Conditions under which the cell can be used for Raman work are summarized. New fluorescence and Raman features are reported for diamond. In particular, a band at 1730 cm⁻¹ is characteristic of type I stones and may be due to C to N bond stretching at defect centers.