|Dec7-08, 02:26 AM||#1|
Calculate lattice constant from x-rays
1. The problem statement, all variables and given/known data
When x-rays are diffracted off NaCl, constructive interference is observed at an angle of 16.3 degrees. Determine the lattice constant of NaCl.
Frequency of the X-ray is 1.948 x 10^18 hz
Theta = 16.3 degrees
2. Relevant equations
(As far as what we're told to use and what's in the book)
2d * Sin (Theta) = m * Lambda
3. The attempt at a solution
After looking through the problem it is very clear that I am unable to find the "lattice constant" from the information given in the book.
I've found the following equations:
1) d = a/sqrt(h2+k2+l2)
2) Lambda/2a= sin 2 Theta/h2+k2+l2
I've tried deriving #2 down to where it is usable and I get:
a2 = (Lambda2/4) * (h2+k2+l2/Sin2 Theta)
I've been unable to figure out what the miller indices are (h k and l), but everything I've tried doesn't get anywhere near the values expected online of 5.63-5.65.
Am I going about this completely wrong or am I just overthinking the problem?
Any help would be much appreciated.
|Dec8-08, 02:14 AM||#2|
I don't think you can figure out the Miller indices if you don't know the orientation of the crystal anyway, right? (It's been a while since I took solid state.)
EDIT: I don't get 5.63 (Angstoms?) either (for any value of m).
|Similar Threads for: Calculate lattice constant from x-rays|
|Lattice Constant||Advanced Physics Homework||20|
|How do you calculate the lattice parameters c and a of Hexagonal ZnO||Atomic, Solid State, Comp. Physics||7|
|Difference between bond length and lattice constant||Chemistry||1|
|Lattice constant of martensite?||Atomic, Solid State, Comp. Physics||2|
|Calculate the lattice constant of a body-centered cubic iron||Advanced Physics Homework||1|