Aqueous Chemistry in the Diamond Anvil Cell up to and Beyond the Critical Point of Water
The chapter discusses the aqueous chemistry in the diamond anvil cell. The hydrothermal diamond anvil cell (HDAC) has been developed or the study of fluids and their interactions with other phases. Visual, spectroscopic, and x-ray methods are used to analyze samples by taking advantage of the exceptional transparency of the diamond anvils. The description of diamond cell configuration, analytical methods, and examples of applications provide evidence of the utility of the technique for many studies of fluids at temperatures and pressures up to and beyond the critical point of water. The HDAC is presented in a diagram and the interactions explained. The analytical techniques covers the extraordinary properties of diamond including hardness, high thermal conductivity, and transparency over large portions of electromagnetic spectrum make it an ideal material for anvils that also serve as windows. Details are provided for visual, X-ray diffraction (XRD), X-ray fluorescence (XRF), and X-ray absorption fine structure (XAFS) techniques. The examples section covers the analytical techniques to investigate properties of fluids, reactions between fluids and solids, and the melting of solids under water pressure.