Download presentation
1
Don’t Ever Give Up!
2
X-ray Diffraction Typical interatomic distances in solid are of the order of an angstrom. Thus the typical wavelength of an electromagnetic probe of such distances Must be of the order of an angstrom. Upon substituting this value for the wavelength into the energy equation, We find that E is of the order of 12 thousand eV, which is a typical X-ray Energy. Thus X-ray diffraction of crystals is a standard probe.
3
Wavelength vs particle energy
4
Bragg Diffraction: Bragg’s Law
5
Bragg’s Law The integer n is known as the order of the corresponding
Reflection. The composition of the basis determines the relative Intensity of the various orders of diffraction.
6
Many sets of lattice planes produce Bragg diffraction
7
Bragg Spectrometer
8
Characteristic X-Rays
9
Brehmsstrahlung X-Rays
10
Bragg Peaks
11
X-Ray Diffraction Recording
12
von Laue Formulation of X-Ray Diffraction
13
Condition for Constructive Interference
14
Bragg Scattering =K
15
The Laue Condition
16
Ewald Construction
17
Crystal and reciprocal lattice in one dimension
18
First Brillouin Zone: Two Dimensional Oblique Lattice
19
Primitive Lattice Vectors: BCC Lattice
20
First Brillouin Zone: BCC
21
Primitive Lattice Vectors: FCC
22
Brillouin Zones: FCC
23
Near Neighbors and Bragg Lines: Square
24
First Four Brillouin Zones: Square Lattice
25
All Brillouin Zones: Square Lattice
26
First Brillouin Zone BCC
27
First Brillouin Zone FCC
29
Experimental Atomic Form Factors
30
Reciprocal Lattice 1
31
Reciprocal Lattice 2
32
Reciprocal Lattice 3
33
Reciprocal Lattice 5
34
Real and Reciprocal Lattices
Atoms are represented by dots. Two atoms per site, connected by straight lines.
35
von Laue Formulation of X-Ray Diffraction by Crystal
36
Reciprocal Lattice Vectors
The reciprocal lattice is defined as the set of all wave vectors K that yield plane waves with the periodicity of a given Bravais lattice. Let R denotes the Bravais lattice points;consider a plane wave exp(ik.r). This will have the periodicity of the lattice if the wave vector k=K, such that exp(iK.(r+R)=exp(iK.r) for any r and all R Bravais lattice.
37
Reciprocal Lattice Vectors
Thus the reciprocal lattice vectors K must satisfy exp(iK.R)=1
38
Brillouin construction
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.