1/14/2015phy 752 spring 2015 -- lecture 21 phy 752 electrodynamics 9-9:50 am mwf olin 107 plan for...
TRANSCRIPT
PHY 752 Spring 2015 -- Lecture 2 11/14/2015
PHY 752 Electrodynamics9-9:50 AM MWF Olin 107
Plan for Lecture 2:
Reading: Chapter 1 & 2 in MPM;
Crystal structures and brief introduction to group theory
1. Survey of crystal structures
2. Elements of symmetry
3. Some ideas of group theory
PHY 752 Spring 2015 -- Lecture 1 21/12/2015
PHY 752 Spring 2015 -- Lecture 2 31/14/2015
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Some common crystal forms found in nature
Note: Materials from Marder used in preparing this lecture.
PHY 752 Spring 2015 -- Lecture 2 51/14/2015
NaCl
Face-centered-cubic with basis
Example materials
PHY 752 Spring 2015 -- Lecture 2 61/14/2015
CsCl
Simple cubic structure with basis
Example materials
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CaF2
Face-centered-cubic with basis
Example materials
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Face-centered-cubic with basis
Zincblende
Example materials
PHY 752 Spring 2015 -- Lecture 2 91/14/2015
ZnS - Wurtzite
Hexagonal structure with basis
Example materials
PHY 752 Spring 2015 -- Lecture 2 101/14/2015
Perovskite
Cubic lattice with basis
Example materials
PHY 752 Spring 2015 -- Lecture 2 111/14/2015
Systemization of crystal forms 14 Bravais lattices 32 Point groups 230 Space groups
Short digression on abstract group theory
• What is group theory ?• What is it doing in the course ?
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Short digression on abstract group theory What is group theory ?
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Short digression on abstract group theoryWhat is group theory doing in a solid state physics class?
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Example of space group theory in band structure analysis
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Example of a 6-member group E,A,B,C,D,F,G
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Check on group properties:1. Closed; multiplication table
uniquely generates group members.
2. Unit element included.3. Each element has inverse.4. Multiplication process is
associative.
DefinitionsSubgroup: members of larger group which have the property of a groupClass: members of a group which are generated by the construction 1 and are group eleme wh nere t si i i YX YX XC=