This preview shows pages 1–2. Sign up to view the full content.
EEE 352—Fall 2009
Homework 1
1.1
Determine the number of atoms per unit cell in a (a) facecentered cubic, (b)
bodycentered cubic, and (c) diamond lattice.
(a) The body centered cubic has 8 corner atoms, each of which is shared among 8
unit cells, so this gives 1 atom.
Then, there are 6 face atoms, each of which is
shared among 2 cells, so this gives 3 atoms.
Hence, the FCC has 1+3 = 4 atoms
per unit cell.
(b) The bodycentered cubic has 8 corner atoms, each of which is shared among 8
unit cells, so this gives 1 atom.
Then, there is 1 atom at the center of the cube.
Hence, the BCC has 1+1 = 2 atoms per unit cell.
(c) The diamond lattice has the FCC cell with 2 atoms per position.
This gives
the additional 4 internal atoms.
Hence, the diamond lattice has 2(1+3) = 1+3+4 =
8 atoms per unit cell.
1.2
(a) The lattice constant of GaAs is 5.65 Å.
Determine the number of Ga atoms
and As atoms per cm
3
. (b) Determine the volume density of germanium atoms in a
germanium semiconductor.
The lattice constant of germanium is 5.65 Å.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '08
 Ferry

Click to edit the document details