Abstract

Understanding and modeling of physics and chemistry of interiors of planets and moons require knowledge on properties of planetary materials under extreme pressure-temperature (P–T) conditions. The past few decades have witnessed the success of combining synchrotron X-rays with static high pressure techniques, large volume press and diamond anvil cell, for in situdetermination of elastic and viscoelastic properties of minerals and rocks. This talk will highlight recent work on the viscoelastic properties of liquid iron-rich alloys using synchrotron X-rays and large volume press. Specifically, the work on the structure, density, and viscosity of Fe-Ni-C liquids determined from both experiments and computations will be introduced in the context of establishing a systematic data set on the density, sound velocity, viscosity, and structure of the liquids in a previously unexplored pressure-temperature-composition sector. Stringent tests of carbon-rich core composition models for the outer core hinges on the liquid properties determined from this research. Prospect of a home synchrotron facility for such high-pressure research will be discussed.