Chapter 3 Flashcards
Amorphous Materials
Short range but no long range order
fast cooling favors an amorphous state
Crystalline Materials
Long range order
Slow cooling favors crystal formation
Lattice
Periodic collection of points where atoms in a crystal are located
Basis
Atom or set of atoms that goes at each lattice point
Unit Cell
Smallest subdivision pf the crystal from which it can be reconstructed by tiling
Simple Cubic Lattice
No particle on the face or center of volume
Body Centered Cubic
A particle in the center of the volume
Face Centered Cubic
A particle on each face of the volume
Miller Indices
For Direction
1) Form a vector in units of the lattice parameter
2) Clear fractions and reduce to lowest integer
3) Single directions go in [ ] with no commas, negative numbers have bars over them
4) Families of related directions go in < >
Miller Indicies
For Planes
1) Find intercepts of the plane. If parallel to an axis the intercept is infinity, if plane passes through the origin, shift origin exactly one unit
2) Take reciprocal
3) Clear fractions, don’t need to reduce
4) Single directions go in ( ) with no commas, negative numbers have bars over them
5) Families of related directions go in { }
Volume Packing Fractions
Volume of atoms in a unit cell / volume of the cube
Areal Packing Fraction
Area of atoms on the face of a unit cell / Area of the cube’s face