Jan 22

Question 1

What are and the orientation of the vectors and angles of the unit cell relative to xyz

Answer 1

Vectors are right-handed, not always orthogonal (90 degrees). For xyz it is abc.

For angles, it is alpha between BC, B between AC, y between AB

Question 2

What are is the reasoning for what plane designation is?

Answer 2

it is abc, looking at how many times this perticular plane cuts across each plane. So a plane that cuts across a once, b twice, and c 3 times is plane 123.

Question 3

What are the miller indices for any planes parallel to a,b,c?

Answer 3

For planes parallel to a, it is 0kl, then h0l for B and hk0 for c.

Question 4

Can you have negative miller indices?

Answer 4

Yes, you go perpendicular to the planes and if points towards +,- this is towards x pos, y neg. This means that for a 210 plane, the 1 is neg.

Question 5

What is Bragg’s law?

Answer 5

2dsin(theta)=n x lambda

d is distance between hkl planes. lambda is wavelength of x-rays. n is an integer (1,2,3,….) Theta is the angle that xrays hit the planes