Thuc tap ve phan tich TEM

Exercise: Indexing of the electron diffraction patterns Louisa Meshi

Formation of electron diffraction and HRTEM image

Ewald sphere construction: ,[object Object],sin  = = = g/2 1/  1/  1/d hkl * 1/2 =  /2d hkl Bragg’s law g hkl O P hkl Origin of the reciprocal lattice 2  specimen 1/  Points of reciprocal lattice (hkl) plane

For diffraction in electron microscope: ,[object Object],specimen Ewald sphere (1/  >>g) 1/  Camera Length (L) r L r = 1 g ; rd hkl =L  , L  - camera constant r

Types of electron diffraction patterns: ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Ring pattern: ,[object Object],[object Object],[object Object],[object Object],[object Object],beam O hkl sphere D

Spot pattern ,[object Object],O g 1 g 2 g 3 Crystal beam Ewald sphere Reciprocal lattice plane h 1 k 1 l 1 h 2 k 2 l 2 beam Zone of reflecting planes B – is a zone axis B Schematic representation of diffraction pattern: Real diffraction pattern: h 1 k 1 l 1 h 2 k 2 l 2

Indexing the SAED pattern (spot pattern): ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],h 1 k 1 l 1 h 2 k 2 l 2 h 3 k 3 l 3  1  2 R 3 R 1 R 2 Zone axis of the ED pattern = (h 1 k 1 l 1 ) (h 2 k 2 l 2 )

Practice time: ,[object Object],[object Object],[object Object]

Thuc tap ve phan tich TEM

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Thuc tap ve phan tich TEM

Similar to Thuc tap ve phan tich TEM (20)

More from luyenkimnet

More from luyenkimnet (20)

Recently uploaded

Recently uploaded (20)

Thuc tap ve phan tich TEM