140
Si
source : X-ray Cu-Ka1 1,540598
2Theta : 20,000 - 140,000
geometry : Bragg-Brentano, fixed slit,
no anom. disp.
130
135
335
125
026
120
H K L 2Theta/deg d/Å
I/rel. |F(hkl)|
____________________________________
115
244
135
110
100,00 59,60
67,10 69,74
39,94 46,21
0,00
0,00
10,70 60,10
16,19 40,66
23,14 53,66
10,17 36,46
3,39 36,46
9,18 48,34
18,41 32,91
0,00
0,00
20,62 43,78
12,01 29,87
100
105
044
90
95
115
80
85
224
70
75
133
222
60
65
004
50
55
113
25
30
35
40
45
022
20
3,13501
1,91979
1,63721
1,56751
1,35750
1,24573
1,10839
1,04500
1,04500
0,95990
0,91784
0,90500
0,85856
0,82807
0
28,447
47,311
56,133
58,868
69,144
76,392
88,049
94,974
94,974
106,735
114,123
116,676
127,585
136,944
5562
1
0
1
2
0
1
2
1
3
0
1
2
0
3
Si
1
2
1
2
0
3
2
1
3
4
3
4
2
3
11124
1
2
3
2
4
3
4
5
3
4
5
4
6
5
FCC unit cell with four atoms:
000, ½ ½ 0, ½ 0 ½ , 0 ½ ½ positions
Fg is non-zero only if all hkl are all
even or all odd
More atoms in the unit cell can result
in additional restrictions.
Si:+ ¼¼¼, ¾¾¼, ¼¾¾, ¾¼¾
FCC [001] zone axis
Structure factor:
N
Fg=

fnexp(2π i(hxn+kyn+lzn))
1
rn=[xn, yn, zn] position vector for
atom n in the unit cell
c
ba
PowderCell 2.0
R2
R1
R3
R4
R1 = 0.50 mm and corresponds to the 111 reflection
R3 = R1, R4 = 0.58 mm and R2 = 0.815 mm
1. What is the camera constant?
2. Calculate the d-values corresponding to R2 and R4
3. Index the diffraction pattern?
4. Find the zone axis.
5. Why do we see the reflection corresponding to R4 by ED and not
XRD?
6.What would the [100] projection look like (compare with FCC ED
diffraction pattern).