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 propeties (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.

Partnership and Collaboration

UT Austin’s Mineral Physics Group is an academic partner of the DCO (Deep Carbon Observatory) and EFree (Energy Frontier Research in ExtremeEnvironments), two frontier research programs that focus on studying material properties in extreme pressure-temperature conditions. Dr. Lin is a visiting professor at Okayama University at Misasa, and is also a member of the SNAP: Instrument Development Team (IDT). These programs provide collaborative research resources and facilities to the UT Austin’s researchers and collaborators:

HPSTAR (High Pressure Science and Technology Advanced Research): HPSTAR has three research branches at Shanghai, Changchun, and Beijing.

DCO (Deep Carbon Observatory): the program is initiated by the Sloan Foundation. Dr. Lin’s group focuses on the investigation of the physics and chemistry of carbon-bearing materials at extreme pressures and temperatures of the deep Earth.
The Deep Carbon Observatory (DCO) is a multidisciplinary, international initiative dedicated to achieving a transformational understanding of Earth’s deep carbon cycle, including its poorly constrained reservoirs and fluxes, the unknown role of deep biology, and unexplored influences of the deep carbon cycle on critical societal concerns related to energy and environments.

EFree: one of the Department of Energy’s 46 Energy Frontier Research Centers (EFRCs), a program initiated in 2009 led by Dr. Ho-kwang (Dave) (the director). Extreme environments of pressure and temperature have long been known to affect radical changes on the structure and properties of matter. The goal of the EFree Center is to explore these and, in particular, to uncover new materials with important relevance for energy based applications. Our focus is to conduct the fundamental research which will underpin the technological advances of the future. The Center’s broad partnership encompasses 8 partner universities and 3 national laboratories, in an effort that is coordinated by the Geophysical Laboratory of the Carnegie Institution of Washington. We hope to accelerate the progress of science by exploiting through a large-scale, multifaceted research program.

HPSynC: The program provides a new approach to high-pressure science using synchrotron radiation. Its mission is to establish high-pressure environments at many beamlines of the APS for the science community, to make novel synchrotron techniques available to high-pressure researchers, and to establish a gateway for high-pressure scientists to many beamlines of the APS.

ISEI:  Dr. Lin is a visiting professor at the Institute for Study of the Earth’s Interior (ISEI) at Okayama University at Misasa. The Visiting Professorship provides resources for international collaborative research at Misasa. Dr. Lin spends time at the Institute conducting deep-Earth research projects.

TMI: Dr. Lin is an Affiliated Faculty at the Texas Materials Institute (TMI) at UT Austin. The TMI was established in 1998 to ensure that UT-Austin achieves excellence in graduate education and research in the broad field of materials. The role of TMI is to be a “virtual” department that guides the destiny of materials science and engineering on the UT campus without imposing the limitations or boundaries inherent to departmental structures.

SNAP: IDT: The IDT of the Spallation Neutrons and Pressure Diffractometer (SNAP) aims to develop “cutting-edge neutron high-pressure instrumentation” at the Spallation Neutron Source, Oakridge National Lab. Dr. Lin is a member of the team and will help to develop new capabilities for studying iron-based superconductors at HP and LT as part of the EFree mission.

Research Keywords

Mineral physics, planetary ices and interiors, iron and iron alloys in Earth’s core, solid-Earth geophysics and geochemistry, mineralogy, spin transition in Earth’s mantle, silica and silicate glasses and melts, water and water chemistry, materials synthesis, transition metal compounds, diamond anvil cell, high pressure-temperature laser heating and external heating, optical spectroscopy, synchrotron radiation in the Earth sciences, X-ray diffraction, X-ray emission spectroscopy, nuclear resonant inelastic X-ray scattering, synchrotron Mossbauer spectroscopy, X-ray 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)