Chaper 2. Wave Diffraction and

the Reciprocal Lattice

d sin

d

Case 1:

Case 3:

Case 2:

1 and 1a

Phase difference between XX’ and YY’

0coscos PKPKPRQK Constructive!!

Case 1:

d sin

d

nd sin2Case 2:

Phase difference between AC’ and AB+BC

sin2costan

2

sin

2

costan

2cos

,tan

2cos2,

sin

ddd

CABCAB

dACCA

dABAC

dBCAB

Case 3:

sin2d

Since d is thickness between layers in which we are interested ,

n indicates the adjacent plane in which the diffraction occurs

2sin2 d

d

d

nd sin2Meaning of n in

1

2

1

3

Scattering 1 , 2: Phase difference

Scattering 1 , 3: Phase difference 2

Scattering 1 , 4: Phase difference 3

nd sin2

Scattering 1 , n+1: Phase difference n

fm, x :Sin 1

2m x^ 2

Sin 1

2x^ 2

10 5 5 10

10

20

30

40

50

60

10 5 5 10

20

40

60

80

100

1 2 3 4 5 6

5

10

15

4m

8m

10m

Ch 2. Prob. 4