Difference between revisions of "Walther453Fall13 Topic12" - Rhea

Revision as of 06:13, 17 November 2013

Crystals and Symmetry

Jason Krupp (krupp@purdue.edu)
Erik Plesha (eplesha@purdue.edu)
Andrew Wightman (awightma@purdue.edu)
Thilagan Sekaran(trajasek@purdue.edu)

A) Crystal Symmetries and Their Properties
--Miller Indices
--Slip Systems
--Group Properties
B) Crystal Movement and Symmetry
--Translational Movement
--Rotational Movement
--Mirror Movement
C)Combinations of Symmetry Operations
--32 Crystal Classes
D)Crystal Symmetry Groups
--Finite Symmetry Groups
--Non-Finite Symmetry Groups

Many important material properties depend on crystal structure. Some of these
include the following inexhaustive list: conductivity, magnetism, stiffness, and
strength.
Miller Indices represent an efficient way to label the orientation of the crystals.
For planes, the Miller Index value is the reciprocal of the value of the
intersection of the plane with a particular axis, converted to whole numbers. For
directions in a crystal lattice, the index is the axis coordinate of the end point
of the vector, converted to the nearest whole number.

For example, the figure above depicts 3 of the 6 cube faces and the corresponding
Miller Indices. The red plane is labeled as (100) because the plane is shifted 1
unit in the x-direction. The yellow plane is labeled (010) because it is shifted 1
unit in the y-direction. Finally, the green plane is labeled (001) because it is
shifted 1 unit in the z-direction.

Gallian, J. (2013). Contemporary abstract algebra. (8th ed.). Boston, MA: Brooks/Cole, Cengage Learning.