Homework 2
Due: 9/11/25
1. Determine the density of GaAs given the lattice constant a = 5.65 Å, and the atomic
weight of Ga is 69.72g/mol and that of As is 74.92g/mol. Avogadro’s number is
6.02x1023 atoms (molecules)/mole.
2. Label the following plane using Miller indices.
z
z
y
y
x
x
(1)
z
x
(2)
(3)
3. Find the Bragg angle of an In0.51Ga0.49As crystal if (004) reflection is used. The lattice
parameters for InAs and GaAs are 6.0582 Å and 5.6533 Å, respectively. The x-ray
wavelength is 1.5406 Å.