X ray spectroscopy tools for the characterization of nanoparticles

1. X-Ray Spectroscopy Tools for the
Characterization of Nanoparticles
Presented By
Md. Sayedul Islam
Ph. D Student
ID: 1016034001
Department of Chemistry
Bangladesh University of
Engineering & Technology
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2. There are various techniques for the characterization of
nanoparticles on the basis of the x-ray such as-
• XRD SPECTROSCOPY
• XPS SPECTROSCOPY
• XRF SPECTROSCOPY etc.
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3. • The contents of the topic are as follows-
• what is XRD?
• History of XRD
• Basic Principle of XRD
• Instrumentation
• Peak analysis
• What type of information obtain from XRD?
• Conclusion
• References
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XRD spectroscopy technique for the
characterization of nanoparticles

4. What is XRD?
• X-ray diffraction is based on the scattering of x-ray by crystal.
• “ Every crystalline substance always gives a pattern, the same
substance always gives the same pattern and in a mixture of
substance each produces its pattern independently of other”.
• So x-ray diffraction pattern of a pure substance is called the
finger print of that substance.
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5. A Brief History of XRD
• 1895- Röntgen publishes the discovery of X-rays.
• 1912- Laue observes diffraction of X-rays from a crystal.
The father and son team of Sir William Henry and William
Lawrence Bragg were awarded the Nobel prize for physics "for
their services in the analysis of crystal structure by means of
X-rays“ in 1915.
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Wilhelm Conrad
Röntgen (1845-
1923)

6. Bragg’s law is a simplistic model to understand what conditions
are required for diffraction.
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7. Information from Bragg’s law for XRD
We can know the following two main informations from Bragg
law-
• The space between diffracting planes of atoms determines
peak positions.
• The peak intensity is determined by what atoms are in the
diffracting plane.
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8. Basic Principle of XRD
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9. 9

10. Challenge of applying XRD to nanotechnology
• Traditional X-ray powder-diffraction techniques rely on
the long-range order in crystals to produce sharp "Bragg
peaks" in a diffraction pattern.
• But in case of nanocrystal due to lack of long-range
order, their diffraction patterns are much more diffused
Bragg peaks.
• "This poses a real challenge to the traditional techniques
for the structure determination of nanoparticle," -- Valeri
Petkov of Michigan State.
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11. Due to overcome this problem Scientist Scherrer use X-rays to
estimate the crystallite size of nanophase materials by the following
equation.
The Scherrer Equation was published in 1918
• Peak width (B) is inversely proportional to crystallite size (L)
• P. Scherrer, “Bestimmung der Grösse und der inneren Struktur von
Kolloidteilchen mittels Röntgenstrahlen,” Nachr. Ges. Wiss. Göttingen
26 (1918) pp 98-100.
• J.I. Langford and A.J.C. Wilson, “Scherrer after Sixty Years: A Survey
and Some New Results in the Determination of Crystallite Size,” J.
Appl. Cryst. 11 (1978) pp 102-113. 11
 



cos
2
L
K
B 

12. Factors that affect K and crystallite
size analysis-
• how the peak width is defined
• how crystallite size is defined
• the shape of the crystal
• the size distribution
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13. Peak Width Broadening
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66 67 68 69 70 71 72 73 74
2(deg.)
Intensity(a.u.)
Peak Width varies inversely with crystallite size as the crystallite
size gets smaller, the peak gets broader.
The peak width varies with 2ө as cos ө.

14. How is Crystallite Size Defined
• For a distribution of sizes, the mean size can be defined as
– the mean value of the cube roots of the individual
crystallite volumes.
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15. Crystallite Size is Different than
Particle Size
• A particle may be made up of several different crystallites.
• Crystallite size often matches grain size, but there are exceptions.
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16. Crystallite Shape
• Though the shape of crystallites is usually irregular, we can
often approximate them as:
– sphere, cube, tetrahedra, or octahedra
– needles or plates
– prisms or cylinders
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17. Non-Uniform Lattice Distortions of nanocompound
• Non-Uniform Lattice Distortions produces a broader observed
diffraction peak.
• Such distortions can be introduced by:
– surface tension of nanocrystals
– morphology of crystal shape, such as nanotubes
– interstitial impurities
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26.5 27.0 27.5 28.0 28.5 29.0 29.5 30.0
2(deg.)
Intensity(a.u.)

18. Sample Deposition – Flat Plate (Bragg-
Brentano)
• plastic, aluminum or glass sample holder: dry
sample in hollow space
• avoid vertical loading (preferred orientation
effects)
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19. fig: Bruker D8 Analytical X-ray
Systems
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20. Information from XRD
XRD gives the information of a nanosample about the following -
Structure determination
Phase identification
Percent of crystallinity
Crystallite size and microanalysis
Texture analysis
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21. Conclusion
• XRD is a powerful tool for answering some specific questions
about a given nanosample-
• Phase present
• Orientation
• Residual stress
• Texturing
• QPA
• Crystallite size analysis.
• XRD is extremely efficient for the characteristic of the sample
due to data acquisition is straight forward and short set up time
is required.
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22. Textbook References
• HP Klug and LE Alexander, X-Ray Diffraction Procedures for
Polycrystalline and Amorphous Materials, 2nd edition, John Wiley & Sons,
1974.
– Chapter 9: Crystallite Size and Lattice Strains from Line Broadening
• BE Warren, X-Ray Diffraction, Addison-Wesley, 1969
– reprinted in 1990 by Dover Publications
– Chapter 13: Diffraction by Imperfect Crystals
• DL Bish and JE Post (eds), Reviews in Mineralogy vol 20: Modern Powder
Diffraction, Mineralogical Society of America, 1989.
– Chapter 6: Diffraction by Small and Disordered Crystals, by RC
Reynolds, Jr.
– Chapter 8: Profile Fitting of Powder Diffraction Patterns, by SA
Howard and KD Preston
• A. Guinier, X-Ray Diffraction in Crystals, Imperfect Crystals, and
Amorphous Bodies, Dunod, 1956.
– reprinted in 1994 by Dover Publications 22

23. Articles
• D. Balzar, N. Audebrand, M. Daymond, A. Fitch, A. Hewat, J.I. Langford,
A. Le Bail, D. Louër, O. Masson, C.N. McCowan, N.C. Popa, P.W.
Stephens, B. Toby, “Size-Strain Line-Broadening Analysis of the Ceria
Round-Robin Sample”, Journal of Applied Crystallography 37 (2004) 911-
924
• S Enzo, G Fagherazzi, A Benedetti, S Polizzi,
– “A Profile-Fitting Procedure for Analysis of Broadened X-ray
Diffraction Peaks: I. Methodology,” J. Appl. Cryst. (1988) 21, 536-542.
– “A Profile-Fitting Procedure for Analysis of Broadened X-ray
Diffraction Peaks. II. Application and Discussion of the Methodology”
J. Appl. Cryst. (1988) 21, 543-549
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24. • B Marinkovic, R de Avillez, A Saavedra, FCR Assunção, “A Comparison
between the Warren-Averbach Method and Alternate Methods for X-Ray
Diffraction Microstructure Analysis of Polycrystalline Specimens”,
Materials Research 4 (2) 71-76, 2001.
• D Lou, N Audebrand, “Profile Fitting and Diffraction Line-Broadening
Analysis,” Advances in X-ray Diffraction 41, 1997.
• A Leineweber, EJ Mittemeijer, “Anisotropic microstrain broadening due to
compositional inhomogeneities and its parametrisation”, Z. Kristallogr.
Suppl. 23 (2006) 117-122
• BR York, “New X-ray Diffraction Line Profile Function Based on
Crystallite Size and Strain Distributions Determined from Mean Field
Theory and Statistical Mechanics”, Advances in X-ray Diffraction 41,
1997.
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25. Thank You to All
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