Introduction to Volume H of International Tables for Crystallography Powder Diffraction ·...
Transcript of Introduction to Volume H of International Tables for Crystallography Powder Diffraction ·...
Introduction to Volume H of International Tables for Crystallography
Powder Diffraction
James A. Kaduk Poly Crystallography Inc.
Naperville IL 60540 [email protected]
Synchrotron Radiation
• Production of synchrotron radiation – Bending magnets, insertion devices
• Optics – Monochromators, mirrors, compound refractive lenses
• Diffractometers • Experimental factors
– Polarization, radiation damage, beam heating, choice of wavelength, angular and spatial and time resolution
Sample (Specimen) Preparation
• Particle statistics • Preferred orientation • Absorption (surface roughness),
microabsorption, and extinction • Specimen holders – reflection, transmission,
zero background, capillaries • Neutron powder diffraction
9. Sample Environment – Magnetic and Electric Fields in
Powder Diffraction H. Ehrenberg and H. Fuess
16. Qualitative Analysis – Whole Powder Pattern Modeling:
Microstructure Determination from Powder Diffraction Data
Matteo Leoni
0 2 4 6 8 10 12 140
5
10
15
20
25
30
35
40 TEM WPPM
fre
quen
cy
grain diameter D (nm)
Size Distribution in Ceria Powder
Size Distribution of Cuprite
0 2 4 6 8 10 12 14 16 18 20 22 240.00
0.05
0.10
0.15
0.20
0.25
g(D)
(ar
b. u
nits
)
D (nm)0 2 4 6 8 10 12 14 16 18 20 22 24
0
10
20
30
40
50
60
70
g(D)
D3 (ar
b. u
nits
)D (nm)
Powder Diffraction File
• History • Search/match algorithms • Quality marks • Features • Boolean logic – trace analysis
Structural Databases
• Cambridge Structural Database – Mercury • Inorganic Crystal Structure Database
– ANX, reduced cell, distance searches • Pearson’s Crystal Data • Metals Data File • Protein Data Bank – calculation of protein patterns • Crystallography Open Database • Other internet resources
19. Qualitative Analysis – The Clustering and Visualization of
Powder Diffraction Data Chris Gilmore
Aspirin data into which 5 amorphous samples have been incorporated. (a) The resulting dendrogram with the amorphous samples isolated at the right side of the dendrogram. (b) The corresponding MMDS plot, with the amorphous samples isolated.
20. Standards and instrument Performance – The Optics,
Alignment, and Calibration of the Bragg-Brentano Laboratory X-ray
Diffractometer Jim Cline, David Black, Donald
Windover, and Albert Henins
Quantitative Phase Analysis
• Classical and Rietveld • Alternative methods
– Phase and instrument constants • PONKCS • Quantification of amorphous material • QPA from energy-dispersive data • Increasing accuracy
23. Solving Crystal Structures – An Overview of Currently Used
Structure Determination Methods for Powder Diffraction Data
Kenneth Shankland
Structure Solution • Conventional and modified direct methods • Patterson function • Resonant scattering • Isomorphous replacement • Maximum entropy methods • Charge flipping • Molecular envelopes • Model building • Molecular replacement • Global optimization
24. Solving Crystal Structures – Reciprocal Space Methods
Angela Altomare, C. Cuocci, A. Moltineri, and R. Rizzi
Reciprocal Space Methods
• Patterson, maximum entropy, direct methods, charge flipping
• Direct methods • Structure model optimization
• Fourier recycling, weighted least squares, resolution bias modification
• EXPO
25. Solving Crystal Structures – Real Space Methods for Structure Solution from Powder Diffraction
Data: Application to Molecular Structures
Bill David
26. Solving Crystal Structures – The Use of Supplementary Information
to Solve Crystal Structures Alistair Florence
Supplementary Information
• Molecular volume • Bond lengths and angles • Flexible ring conformations • Torsion angle constraints • Solid state NMR information • Intermolecular distance constraints • Hydrogen atoms • Crystal structure prediction
41. Solving Crystal Structures – Solving and Refining Zeolite
Structures Lynne McCusker and Christian Baerlocher
Rietveld Refinement
• History • Rietveld vs. single crystal refinements • Multiphase and multi-dataset fitting • Mechanism of Rietveld fitting • Agreement factors • Restraints and constraints • The order to introduce parameters in a fit
Structure Validation
• Statistical measures (with Brian Toby) • Graphical measures (with Brian Toby and Judy Stalick)
• Chemical reasonableness – Organic and inorganic
• checkCIF/PLATON
XRD and DFT
Cations Reference Experiment RMS Δ, Å
H3 CITRAC10 Single crystal 0.030a
H3(H2O)1 CITARC Single crystal 0.036a
Li1H2 LIHCIT Single crystal 0.418a
Li1(H2O)1 PIGPUQ Single crystal 0.082c
Li3(H2O)4 FUQFUS Single crystal 0.091c
Li3(H2O)5 CADJIA Single crystal 0.101c
Na1H2 New powder Powder 0.261a
Na1H2 NAHCIT Single crystal 0.040a
Na2H1(H2O)1.5 New single crystal Single crystal 0.048b
Na3 New powder Powder 0.080a
Na3(H2O)2 UMOGAE Single crystal 0.068c
RMS differences (Å) between the non-hydrogen atoms in experimental and DFT optimized crystal structures of Group 1 citrate salts, C6H5O7
3-
Obtainable information SAXS SANS WAXS and WANS (powder
diffraction)
Total scattering
lattice spacings, crystal phases X
mean precipitate or pore
diameter, shape
X X
size distribution X X
pore or particle volume fraction X X
pore or particle surface area X X
composition, density of solid
phases
X X X
interparticle interactions X X
particle or pore pair
distribution function
X X
local structure X X
atomic pair distribution
function
X X
Quantitative Information Available
Small-Angle Scattering
• (U)SAXS tools and optics • Data reduction and calibration • Reflectivity and grazing incidence • Quantitative interpretation • Anomalous and contrast variation SAXS • SAS effects in WAS
Stress and Strain This chapter is a review of the basic concepts, models, methods and approaches in the investigation by diffraction of the stress and strain in polycrystalline materials. The chapter contains eight sections that can be grouped in three parts. In the first part the specific quantities in single crystals and polycrystals are defined Together with the mathematical background. The state of art in the field and the classical models allowing determining the macro strain and stress in the most of samples are described in the second part. The third part is dedicated to the modern analysis by generalized spherical harmonics of the diffraction lines shift and breadth caused by strain in textured polycrystalline sample.
Rendition of the 3D grain structure in a cylindrical beta-Ti specimen containing 1008 Grains, as obtained by the DCT algorithm. From Ludwig et al., 2008.
36. Quantitative Texture Analysis and Combined Analysis
Daniel Chateigner, Luca Lutterotti, and Magali Morales
Thin Films and Multilayers
• Effects of absorption • Grazing incidence configurations • Textures and depth dependence • Stress and strain analysis • X-ray reflectivity • Grazing incidence X-ray scattering
Figure 1. Calculated Debye diffraction response for a single mannitol molecule displayed with the Coherent and incoherent diffraction responses. The Y axis is in electron units.
Figure 8: measured Bragg-Brentano data form Si SRM 640d displayed with the calculated full background response including the instrumental contribution, Brehmstrallung, thermal diffuse scattering and Compton scattering. The Derived instrumental response is shown in red.
Figure 10: Normalized analytical data for dry and partially dry sucrose lyophilizates. Each analytical data set has the same integrated intensity and matching asymptotic behavior towards 70 degrees 2Theta. An additional constraint of matching low angle analytical signal was also imposed during the normalization.
XRPD of Ceramics
• Qualitative and quantitative analysis • Phase equilibria • Phase evolution and transformation • Structure and microstructure
– Size, strain, imperfections, texture, roughness • Processing and performance
– Sintering, kinetics, toughening, …
110
Concentration Errors in Synthetic Portland Cements
Weight Concentration, %10
Con
cent
ratio
n Er
ror,
wt%
abs
olut
e
-3
-2
-1
0
1
2
3
Powder Diffraction and Pharmaceuticals
• Identification and characterization • Indexing • Quantification (crystalline and amorphous) • QC and regulatory issues • Creating and protecting intellectual property • Counterfeit medicines
Forensic XRD • Drugs and toxicology • Paint and pigments • Pathology • Metals and alloys • Soils and minerals • Gunshot residues and explosives • Paper • Polymers • Experimental and procedural issues
58. Application of Powder Diffraction to the Study of Phase
Stabilities in Piezoelectric Ceramics Dhananjai Pandey
MATERIAL NO OF PHASES SAMPLE TYPE
SUCCESS RATE
Bauxite 14 - 24 cavity slide limited
Red Mud 30 - 60 cavity slide limited
Alumina 8 cavity slide limited - high
Electrolytic Bath 9 - 16 briquette, cavity high
Spent Potlining 30 - 60 cavity slide limited - high
Dross 10 - 20 cavity slide high
Intermetallics > 20 cavity slide high
Typical Rietveld Applications in the Aluminum Industry