nuclear resonant scattering under high pressure at hpcat yuming xiao nov 9, 2014, nuclear resonant...
TRANSCRIPT
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
ID-A: First Optics Enclosure
ID-C: Second Optics Enclosure
ID-D: The Experimental Station
X-RAY SPECTROSCOPY BEAMLINE AT HPCAT
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 N2 cooled Si (1 1 1) DCM
Energy range 4.5-35keV
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 57Fe, 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)
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
MembraneMembrane box
Pressure-induced invar behavior in Pd3Fe
Winterrose et al. PRL 102, 237202 (2009)
The NFS revealed a collapse of the 57Fe 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)
Positive Vibrational Entropy of Chemical Ordering in FeV
Munoz et al. Phys. Rev. Letter, 2011
Phonons in the B2 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.
AcknowledgementsSector3, 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