Synchrotron X-ray Facilities

National Synchrotron Light Source
Brookhaven National Laboratory

X17 DAC diamond anvil cell facility (X17C and X17B3)

T. Duffy leads the management team that operates X17 DAC for the Consortium for Materials Property Research in the Earth Science (COMPRES)

The X17 DAC facilities are located on a superconducting wiggler beam line and consist of two stations (X17C and X17B3) together with a sample preparation/spectroscopy laboratory.

Meet the beamline scientists at X17- DAC:

Capabilities:
Both X17C and X17B3 are available for energy dispersive (EDXD) and monochromatic (ADXD) experiments. Monochromatic beams are available with small beam size (10-20 micron) and high flux via Sagittally-bent double Si crystal Laue mode (transmission) monochromators in conjunction with a K-B mirror system. X17C has both focused white beam and monochromatic beam (30KeV) capable of diffraction at extreme condition of pressure and temperature from powder, single crystal and nanocrystal samples. At X17B3 in addition to the EDXD capability two different energy ranges of monochromatic beams are available at 30 keV and 80 keV for achieving angle dispersive diffraction up to a very high Q range to get data for a total scattering geometry. These capabilities are unique in terms of X-ray diffraction data collection at high Q range and higher flux.

Examples of recent projects:
Dong, H., D. He, T. S. Duffy, and Y. Zhao, Elastic moduli and strength of nanocrystalline cubic BC2N from x-ray diffraction under nonhydrostatic compression, Physical Review B, 79, 014105, 2009.

Lin, J.-F., H.-R. Wenk, M. Voltolini, J. Shu, S. Speziale, and T. S. Duffy, Texture and strength of lower mantle ferropericlase across the spin transition, Physics and Chemistry of Minerals, 2009.

X17-IR infrared facility (U2A)

We are also users of U2A which is an infrared beamline optimized for high-pressure experiments in the diamond anvil cell.

Recent project:
Shieh, S. R., T. S. Duffy, Z. Liu, and E. Ohtani, High-pressure infrared spectroscopy of the hydrous magnesium silicates, phase D and phase E, Physics of the Earth and Planetary Interiors, 175, 106-114, 2009.

Advanced Photon Source, Argonne National Laboratory
Argonne National Laboratory

The Advanced Photon Source is a third generation synchrotron source that is the premier x-ray facility in the US. In recent years, our group has been active users of the GSECARS (sector 13) and HPCAT (sector 16) beamlines. A major focus has been to combine diamond anvil cell techniques with laser heating (using a high-powered infrared laser) to simultaneously achieve extremes of pressure and temperature -- up to 300 GPa and 3000 K.

Capabilities include:  laser and external heating, x-ray diffraction of powders and single crystals, x-ray scattering and spectroscopy experiments, Brillouin spectroscopy, high-pressure gas loading, diamond anvil cell and large-volume press apparatus.

In 1995-96, T. Duffy helped to initiate the diamond cell program at GSECARS by serving as the first beamline scientist. The results of the first high-pressure experiments at APS (carried out in 13-ID-A) are published here. We have been regular users of APS facilities ever since.

Examples of recent graduate student projects:

• Suki Dorfman: Pyrope-almandine composition perovskites
• Zhu Mao: High-pressure phases of oxide garnets to multi-Mbar pressures
• Suki Dorfman: Phase transitions and equations of state of alkaline earth fluorides CaF2 and SrF2 to Mbar pressures
• Claire Runge: Equation of state of MgGeO3 perovskite to 65 GPa: comparison with the post-perovskite phase

Duffy Group
High-Pressure Mineral Physics and Materials Science Laboratory
Department of Geosciences
Princeton University