Nuclear Resonant Scattering under High Pressure at HPCAT Yuming Xiao Nov 9, 2014, Nuclear Resonant Scattering Workshop, Argonne, IL

Outline Introduction to 16 IDD of HPCAT Nuclear Resonant Scattering Program at HPCAT Research examples

Introduction to 16 IDD of HPCAT (I)

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 keV APS undulator 3.0

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, (2011) Mao et al. PNAS, 108 (2011)

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

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

Pressure-induced invar behavior in Pd 3 Fe Winterrose et al. PRL 102, (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, (2011)

Magnetic P-T phase diagram of langasite Ba 3 TaFe 3 Si 2 O 14 Gavriliuk et al., APL, 103, (2013)

Tanis et al. unpublished DyFe 3 under high pressure DyFe 3

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.

FeSe under High Pressure Kumar et al. J.Phys.Chem. B, 2010 Kumar et al. APL, 2011

Future Developments and Plans  more working APD detectors  mechanical chopper/shutter  HP-LT NRIXS

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- 06CH HPCAT  Paul Chow  Genevieve Boman  Eric Rod  Curtis Kenny-Benson  Arun Bommannavar  Guoyin Shen

Thank you!