Research

Research Interest

Our research interests focus on materials properties in extreme environments as these can have direct implications to:
–Understanding the mineral physics of the Earth’s interior;
–Understanding the interiors and evolution of planetary bodies;
–Novel materials properties (superhard, superconductors, energy storage, 2-dimensional materials);
–New optical, X-ray, and high-pressure techniques;

Our main area of research interest focuses on understanding the nature of the Earth’s interior and other planetary bodies through direct examination of the properties of planetary materials under high pressure-temperature conditions. We use high pressure-temperature diamond anvil cells combined with in-house optical laser and synchrotron-based X-ray facilities to understand mineral physic of the deep-Earth materials. These studies aim to understand crystal structures, phase relations, physical and transport properties (e.g., sound velocities, electronic spin transitions, equation of state, etc), and chemical reactions of planetary materials under extreme high pressure-temperature conditions. We aim to combine results from other disciplines to enhance our understanding of the interiors of the Earth and other planets.

Another area of our research interest is the behavior of volatiles such as H2O and CO2 under extreme conditions, as they are essential to our understanding of myriad problems in physics, chemistry, biology, and planetary sciences where molecular interactions play important role in these hydrogen-carbon-oxygen compounds. In particular, Earth’s water/carbon cycles and their reactions with planetary materials control the geology, geochemistry, and biology of the planet. Furthermore, many forms of clathrate hydrates such as hydrogen hydrate can be formed by mixing H2, H2O, and/or CH4 under high pressures and temperatures, while understanding properties of CO2 with its surrounding materials is essential to the CO2 sequestration.

We are also interested in high-pressure condensed matter physics and materials sciences in which we explore materials properties under extreme environments. The diamond cell technique coupled with synchrotron X-ray spectroscopies is well suited for this area of research. We are particularly interested in understanding the properties of superconductors (pnictides and cuprates), multi/nano-layered and superhard materials, transition metal and strongly correlated systems in extreme pressure-temperature environments.

 

Research Keywords

Mineral physics, Earth’s interior, planetary interiors, high pressure, iron alloys in Earth’s core, solid-Earth geophysics and geochemistry, mineralogy, spin and phase transitions in Earth’s mantle, iron isotope fractionation, silica and silicate glasses and melts, water and water chemistry, materials synthesis, transition metal compounds, pnictides, methane hydrate, 2D materials, superconducting hydrides, diamond anvil cell, optical spectroscopy, synchrotron X-ray spectroscopy, X-ray diffraction, X-ray emission spectroscopy, nuclear resonant inelastic X-ray scattering, synchrotron Mossbauer spectroscopy, Brillouin light scattering, impulsive stimulated light scattering, Raman spectroscopy.

Current Research Projects

  • Mineral physics of the Earth’s interior
  • Thermo-elastic properties and phase transitions in the lower-mantle silicate perovskite, post-perovskite, and ferropericlase
  • Electronic spin transitions of iron and their consequences in the lower mantle
  • Elasticity and phase diagrams of iron alloys in the Earth’s core
  • Elasticity of upper-mantle minerals (olivine/garnet)
  • Silicate and silica glasses and melts under extreme conditions
  • Volatiles (i.e., H2O and CO2 liquids and ices) in planetary interiors
  • Optical and synchrotron spectroscopies at high pressures and temperatures
  • Water in the deep Earth (elasticity of transition zone minerals)
  • HP materials science (d/f-band metals/compounds, superhard materials)
  • Iron-based superconductors (122 and 1111 pnictides)
  • Deep-carbon cycle and storage; hydrocarbon carbons and carbonates
  • Nanomaterials and electronic materials (graphere, MoS2, and nano- and multi-layered materials)