Nuclear resonant scattering at high pressure and high temperature

Abstract

We introduce the combination of nuclear resonant inelastic X-ray scattering and synchrotron Mössbauer spectroscopy with the laser-heated diamond anvil cell technique for studying magnetic, elastic, thermodynamic, and vibrational properties of materials under high pressures and high temperatures. An Nd:YLF laser, operating in continuous donut mode (TEM₀₁), has been used to heat samples inside a diamond anvil cell from both sides. Temperatures of the laser-heated sample are measured by means of spectral radiometry and by the detailed balance principle of the energy spectra. The temperature measured by the detailed balance principle is in very good agreement with values determined from the thermal radiation spectra fitted to the Planck radiation function up to 1700 K. Nuclear resonant scattering on ⁵⁷Fe-containing materials (i.e., Fe, FeO, Fe₂O₃) has been studied up to 2500 K and 100 GPa. A detailed description of the laser-heating optics, temperature determination, the X-ray monochromatization, and the X-ray focusing optics is given in this article.

Keywords:

• Laser heating
• Diamond anvil cell
• Nuclear resonant scattering
• Synchrotron radiation

Acknowledgements

We thank J. Burke, V. Prakapenka, D. Errandonea, S.-K. Lee, M. Hu, D. Hauserman, M. Yue, M.L. River, S. Hardy, V.V. Struzhkin, D. L. Heinz, G. Steinle-Neumann, R. Cohen, and J. M. Jackson, for their help during our LHDAC system construction and testing. Use of the advanced photon source is supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Office of Science, under contract no. W-31-109-ENG-38. Work at Carnegie was supported by DOE/BES, DOE/NNSA (CDAC# DE-FC03-03NA00144), NASA, NSF, and the W.M. Keck Foundation.