Mechanical and Transport Properties

Transcription

1 Mechanical and Transport Properties Recommendations Techniques (in-situ, time-resolved) Laue µ-diffraction High Energy Diffraction Microscopy (3DXRD) Advanced imaging (phase contrast, tomography) Coherent diffraction Thermo-mechanical loading capabilities Temperature control (resistive heating, laser, cryostat) Triaxial load control (multi-axis press) Shear loading (r-dac, r-drickamer) Hardware Bigger, faster, high-resolution area detectors Spectroscopy techniques Software Big data handling Automated analysis Forward modeling

2 Mechanical and Transport Properties: Important Issues Superhard and ultratough materials Energy-related materials (storage, conversion and transport) Strength, stiffness and equation of state Deformation mechanisms Phase transitions Deep Earth properties

3 electronic, ionic, & molecular transports in crystal structure tin oxide SnO 2 nanowire Thermomechanical stresses related to electrochemistry processes Li-ion battery Formation of fast ionic channels and alignment of preferred orientation How can high-pressure synchrotron/neutron techniques complement? Cathodes! Scientific Challenges Internal Pressure for Cage-Structure Volume restrains in crystal structures related to Lithium intercalation and hydrogen encapsulation?! Technical Challenges How to detect low-z and high-z elements?! Contrasts and Different Scale for Low-Resolution and High-Resolution for Bulk Tomography Characterization

4 Challenges in understanding the material properties via in-situ synchrotron x-ray experiments Superconductivity Mechanisms at low-temperature/high-pressure Eu 2+ Eu 3+ EuFe 2 As 2 Oxides -to- Fe based Valence XAS, Local Spin XES, Structure XRD, Magnetic Ordering NFS/Mossbauer Scientific: Whether charge density wave (CDW) can be probed in-situ at LT/HP along with transport? Technical: Phonon DOS at variable P-T possible? Para- (ambient) Anti- (low-t) LaFeAsO Suppressi on of magnetic ordering No-ordering (high-p)

5 1000 K 3500 K MgSiO 3 Perovskite Miyagi, Kanitpanyacharoen, Kaercher, Lee, Wenk. Science GPa 140 GPa Post-perovskite Wenk, Cottaar, Tome, Romanowicz and McNamara. EPSL 2011

6 sample boundary Laue µ-diffraction can provide new insights into mechanical response in situ What we get: spatially resolved measurements (down to 1µm) of: Lattice orientation/phase Deviatoric strain tensor (3-d) Defect content (dislocations, etc ) What we need: K-B mirrors 90 scattering geometry, transparent gaskets Fast area detectors Streaked laue spots from deformed Si contain information on defects 2D scanning ~65 microns α-fe phase map at 13.5GPa (ALS)

7 High Energy Diffraction Microscopy Bridging the gap between single crystal and powder techniques (3DXRD, HEDM) We get: Fully resolved 3-d lattice vectors for up to 1000 domains simultaneously Full strain tensors In situ technique FAST We need: keV (Laue monochromator) Large, fast area detectors Observation of Burgers mechanism in Fe phase transition at 1-ID 3D strain tomography

8 Deformation experiments with DAC Compression experiments with DAC in radial geometry at high pressure (200GPa) and high temperature (3000K) Pressure and stress Q variation due to stress/elastic properties Intensity variations due to crystal orientation: Plastic deformation Determine anisotropic single crystal elastic properties Identify deformation mechanisms Phase transitions

9 Deformation experiments with rotation DAC: Torsion

10 Expand flexibility for in situ heating with radial DAC ALS HPCAT

11 What can LVP bring to studies of transport properties at high P and T? Sample Volume, mm LVP DAC The large-volume advantage: -- T (thermal conductivity) -- Absorp. (elem. Diffusion) -- Electrical conductivity -- Stress/strain (rheology, Q) -- Ultrasound (Brittle failure) -- etc HPCAT, Oct, Pressure, GPa 11

12 Designed for neutron But can be modified for synchrotron applications Conceptual design for 6-cylinder true tri-axial loading

13 Rotational Drickamer for tomography at GSECARS HPCAT, Oct,

14 Need to investment in development of analysis software Modular Design, Graphical Interfaces Rietveld (MAUD) Diffraction Microscopy (hexrd) Laue (XMAS, LaueTools) Tomography (3D, high resolution) Bottleneck for user community! Big data, automated analysis, forward modeling

15 Mechanical and Transport Properties Suggested Priorities: Laue microdiffraction, imaging Temperature control (heating, cryostat) Time-resolved experiments Triaxial / rotational loading mechanisms Jon Almer, ANL almer@aps.anl.gov Joel Bernier, LLNL bernier2@llnl.gov Changfeng Chen, UNLV chen@physics.unlv.edu Yan-zhang Ma, Texas Tech y.ma@ttu.edu Dmitry Popov, HPCAT dpopov@ciw.edu Yanbin Wang, U Chicago wang@cars.uchicago.edu Rudy Wenk, UC Berkeley wenk@berkeley.edu Yusheng Zhao, UNLV Yusheng.Zhao@UNLV.EDU