xpdf industry slides - goodwin group oxford
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XPDFA Dedicated X-ray PDF BeamlinePhase III Beamline Proposal
DISCO Presentation 24 February 2011
Pair Distribution Function (PDF)
• Quantitative experimental probeof local structure in materials
• Fourier transform of powder dif-fraction pattern; gives histogramof interatomic separations
• Quantifies “true” bond lengths,coordination number, dynamics
• Resolution determined by Qmaxso requires high-energy X-rays
• Applicable to crystals, nanocrys-tals, amorphous materials, liquids
Catalysis
• “Differential PDF” allowsstructural characterisation ofe.g. nanoparticulate catalystsmounted on solid substrates
• Rapid PDF analysis allows for insitu measurements of localstructure changes in real timeduring catalytic processes
• Model-independent observationof interatomic distances;cf EXAFS, NMR
Pt–Pt Differential PDF
TiO2 substrate
NanoparticulatePt catalyst
Chupas, Chapman, Chen and Grey, Catalysis Today 145, 13 (2009)
• Structural characterisation ofamorphous and nanocrystallinedrug materials
• “Fingerprinting” for IP applications• Determination of impact of
processing on solid form ofamorphous products
• Tracking of structural changeswith time, temperature and%R.H.
• Characterisation of crystallisationpathways in amorphousbiomaterials; e.g. a-Ca3(PO4)2
Health and Pharmaceutics
Billinge et al, CrystEngComm 12, 1366 (2010)
Crystalline form 1
Crystalline form 2
Amorphous form
Energy
• Gas sorption dynamics andbinding site preferences inporous materials
• CO2 capture in ionic liquids• In operando measurement of ion
transport mechanisms in batterymaterials
• Parametric studies undervariable temperature, pressure,gas flow, charge/discharge
Digital Economy
• Structure–electronic propertyrelationships in amorphoustransparent conducting oxides
• Local structure and dynamics inthin-film ferroelectrics
• Nanoscale disorder in dilutemagnetic semiconductors forspintronics
• Amorphous–crystalline transitionsin phase change chalcogenidesfor data storage (e.g. DVD-RAM)Matsunaga et al, Nature Materials 10, 129 (2011)
GST Crystal PDF
GST Amorphous PDF
XPDF Beamline Design
• Sidestation to I-15 with high-energy beam profile(superconducting multipole wiggler)
• Cost-effective design maximises scientific potential of existinginfrastructure
• Range of sample environments; 2D detector for rapid and robustdata acquisition
XPDF Industrial Supporters