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Nuclear Resonant Scattering under High Pressure at HPCAT Yuming Xiao Nov 9, 2014, Nuclear Resonant Scattering Workshop, Argonne, IL
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Outline Introduction to 16 IDD of HPCAT Nuclear Resonant Scattering Program at HPCAT Research examples
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Introduction to 16 IDD of HPCAT (I)
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Introduction to 16 IDD of HPCAT (II) 30 (V) x 50 (H) µm with 1-meter KB mirrors 30 (V) x 10 (H) µm with 1- meter vertical KB and 200 mm Horizonttal KB mirrors 4 (V) x 5 (H) µm with 200 mm KB mirrors Bruker liquid N 2 cooled Si (1 1 1) DCM Energy range 4.5-35keV APS undulator 3.0
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Introduction to 16 IDD of HPCAT (III) Techiniques available: Resonance/X-ray Emission Spectroscopy (~1eV energy resolution, LT down to ~10K) Inelastic X-ray Scattering (electronic excitation at low q and core electron excitation at large scattering angle (XRS), ~1eV energy resolution) Nuclear Resonant Scattering (~2meV energy resolution for 57 Fe, LT down to ~4K for NFS , whole cell heating furnace, in-situ XRD) x-ray Lin et al. PRL, 107, 175504 (2011) Mao et al. PNAS, 108 (2011)
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Nuclear Resonant Scattering NRIXS partial density of states (DOS): vibrational kinetic energy, vibrational entropy, Debye temperature, and Debye sound velocity NFS hypefine interactions: valence, spin state and magnetic ordering
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NRS Program at HPCAT ~20% beamtime for NRS program Applications in: Geophysics Condensed Matter Physics Material Science two cryostats for NFS experiments with membrane pressure control, online ruby system Membrane Membrane box
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Pressure-induced invar behavior in Pd 3 Fe Winterrose et al. PRL 102, 237202 (2009) The NFS revealed a collapse of the 57 Fe magnetic moment between 8.9 and 12.3 GPa at 300 K, coinciding with a transition in bulk modulus found by XRD. Winterrose et al. PRB 83, 134304 (2011)
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Magnetic P-T phase diagram of langasite Ba 3 TaFe 3 Si 2 O 14 Gavriliuk et al., APL, 103, 162402 (2013)
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Tanis et al. unpublished DyFe 3 under high pressure DyFe 3
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Positive Vibrational Entropy of Chemical Ordering in FeV Munoz et al. Phys. Rev. Letter, 2011 Phonons in the B 2 ordered phase are softer than in the bcc solid solution. This result is contrary to the behavior of ordering alloys to date. First-principles calculations which showed that electronic screening is enhanced during ordering process and thus the average energy of phonons was reduced.
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FeSe under High Pressure Kumar et al. J.Phys.Chem. B, 2010 Kumar et al. APL, 2011
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Future Developments and Plans more working APD detectors mechanical chopper/shutter HP-LT NRIXS
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Acknowledgements Sector3, APS Ercan Alp Jiyong Zhao Tom Toellner Michael Hu HPCAT 16 ID-D Users HPCAT is supported by CIW, CDAC, UNLV and LLNL through funding from DOE-NNSA, DOE-BES and NSF. APS is supported by DOE-BES, under Contract No. DE-AC02- 06CH11357. HPCAT Paul Chow Genevieve Boman Eric Rod Curtis Kenny-Benson Arun Bommannavar Guoyin Shen
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Thank you!
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