Professor Estrada
ENGR 245: Intro to Materials Science & Engineering
February 3, 2016
In order to receive full credit, all work MUST be shown and appropriate units must
be specied. Working together is encouraged, however, all work that you turn in must be
YOUR OWN work.
Exercise 1. Given:
En = ??A
r + B
rn
Plot the En vs r for the following pair of ions up to 1 nm
Pair 1: A = 2:34 eV-nm, B = 3:34 10??4 eV-nm8, n = 8
Pair 2: A = 1:436 eV-nm and B = 3:34 10??4 eV-nm9, n = 9
Exercise 2. On the basis of your plot in exercise 1, determine which bonding curve would
likely be associated with the material that has the higher melting temperature.
Exercise 3. Show that the ideal c/a ratio is 1.633 for a HCP lattice, and that the APF is
equal to that of the FCC crystal structure.
1

Professor Estrada
ENGR 245: Intro to Materials Science & Engineering
February 3, 2016
In order to receive full credit, all work MUST be shown and appropriate units must
be specied. Working together is encouraged, however, all work that you turn in must be
YOUR OWN work.
Exercise 1. Given:
En = ??A
r + B
rn
Plot the En vs r for the following pair of ions up to 1 nm
Pair 1: A = 2:34 eV-nm, B = 3:34 10??4 eV-nm8, n = 8
Pair 2: A = 1:436 eV-nm and B = 3:34 10??4 eV-nm9, n = 9
Exercise 2. On the basis of your plot in exercise 1, determine which bonding curve would
likely be associated with the material that has the higher melting temperature.
Exercise 3. Show that the ideal c/a ratio is 1.633 for a HCP lattice, and that the APF is
equal to that of the FCC crystal structure.
1