Determining Structure of Crystals

1
Determining Structure of Crystals

• Peter Abeles
• Carnegie Mellon University

2
Outline

• Theory Behind The Experiment (Braggs Law)
• Experimental Setup
• Crystal Structures
• Determining Structures

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Braggs Law

• Bragg Diffraction

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Experimental Setup
5
Structures
6
Missing Peaks
This function determines the intensity of the
peak for LiF crystal.
7
Example
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Conclusion

• Bragg diffraction predicts where peaks should
  occur
• Absence of peaks can be used to determine
  crystalline structure

9
Acknowledgement

• Pictures relating to Braggs Lawhttp//www.physic
  s.sfsu.edu/bland/courses/490/labs/d2/braggthy.htm
  l
• Cool applet of Bragg diffraction at
  http//www.journey.sunysb.edu/ProjectJava/Bragg/ho
  me.html
• Lots of information on crystals
• http//cst-www.nrl.navy.mil/lattice/struk/a2.html