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Stanford Synchrotron Radiation Lightsource
Introduction to Synchrotron X-ray Scattering Techniques
Mike Toney, SSRL Materials Sciences Division
1. Why do x-ray scattering?2. Basics of an x-ray scattering experiment3. SSRL scattering beamlines4. Some examples
Why do SR X-ray scattering?Materials properties are caused or affected by their physical structure and morphologyImprove your materials by understanding the structure.
• Phase identification & quantify• Where are the atoms: Atomic or
Obtain average size & particle/pore size distribution (need large Q range)
• (More) Ordered Structuresparticle/pore spacing and morphology
• Dense Network of Pores/ParticlesObtain representative morphologyGood for interconnected & bicontinuousmorphologies
John Pople, up next!
Example 2: Nanoparticles
+ H2
Motivation:• Pd absorbs hydrogen at an
atomic level• Clusters behave differently to
bulk• Pd clusters:
– size dependence– surface/volume ratio
Nanoparticles: X-ray diffraction
k’Q = k – k’
kk
k’Q = k – k’
k
Reflection Transmission
Point detector(2-1, 7-2)
Nanoparticles: X-ray diffraction
Ingham et al., Phys. Rev. B 78 245408 (2008).
In-situ Experiments – more laterAPS sector 12
Summary: Nanoparticles
Apurva, Linda, Marc, Misra, Yezhou: this afternoon
This work:• Observe peaks
corresponding to fcc Pd• Lattice expansion upon
addition of hydrogen• Dependence on cluster
size
Powder diffraction:• Phase identification• Structure determination• Strain• Crystallite size• Defects• In situ measurements• Transmission and
reflection geometries
k’Q = k – k’
kk
k’Q = k – k’
k
Example 3: ZnOMotivation:•ZnO exhibits a wide variety of nanostructures•Electrochemical processing has many advantages•Experimental parameters determine morphology
100
002
How does crystallography affect the growth of the nanostructures?
Thin Film DiffractionArea
Detector
incident
~ degQ scattered
Beam line11-3 incidentscattered
Detector
Q
ZnO: experimentsEx situ:
100
002
002
100
101
Au
Au
Au
102102
200
ZnO: SummarySummary:•Texture increases with deposition time•Nanostructures are oriented along 002 direction•Films deposited at less negative electrochemical potentials have poorer epitaxy
100
002
Thin films and texture:• Surfaces, interfaces• Structure, strain• Orientation• Crystallite size in-plane
and out-of-plane
Arturas, Chad, Stefan, Chris, this afternoon
Summary• Typical SR x-ray scattering experiment & some examples:
porous films, nanoparticles, textured films
• To be covered in this workshop: • Films: random, textured, epitaxial• SAXS• Powder• Poorly ordered • Surfaces
Speaker Mug Shots
Bibliography
• B Warren, “X-ray Diffraction”, Dover (1990): $7.58 & eligible for FREE Super Saver Shipping on
• BD Cullity & SR Stock, “X-ray Diffraction”, Prentice Hall (2001): $159.16.
• J Als-Nielsen & D McMorrow, “Elements of Modern X-ray Physics”, Wiley (2001): $92.89.
More Bibliography• M. Tolan, “X-ray Scattering from Soft-Matter: Materials Science and Basic
Research”, Springer (1998).• RL Snyder, K. Fiala & HJ Bunge, Eds., “Defect and Microstructure Analysis by
Diffraction”, Oxford (1999).• V Holy, U Pietsch, T Baumbach, “High-Resolution X-Ray Scattering: From
Thin Films to Lateral Nanostructures”, Springer-Verlag, (2004)• O Glatter, “Small Angle X-Ray Scattering”, Academic (1982).• “Modern Aspects of Small Angle X-Ray Scattering”, H. Brumberger (Editor),
Springer (1994).• Int. Union of Crystallography: Links to everything crystallographic.
www.iucr.org . See : www.iucr.org/cww-top/edu.index.html and also Teaching and Education in Crystallography: www.minerals.csiro.au/mirror/w3vlc/edu.index.html.
• Structural data for thousands of minerals: database.iem.ac.ru/mincryst/ • Lawrence Berkeley: X-ray interactions with matter, data & calculations www-
cxro.lbl.gov/optical_constants/ • International Centre for Diffraction Data - purveyors of the Powder Diffraction