Chemistry Reference
In-Depth Information
Table 3.21
Hyperfine parameters of sample C1 at different temperatures
T (K)
B
av
(T)
B
p
(T)
2e/D (mm/s)
d
Fe
(mm/s)
RA (%)
Assignment
300
37.0
49.1
-0.17
0.35
22
Hematite
-
-
0.62
0.34
78
Goethite ? Ferrihydrite
15
52.4
52.5
-0.17
0.47
23
Hematite (WF)
47.9
49.1
-0.20
0.47
32
Goethite
29.7
37.7
-0.06
0.46
19
Ferrihydrite
Fe
3+
-
-
0.69
0.44
26
doublet (Fh)
4
52.5
52.5
-0.17
0.47
27
Hematite (WF)
48.6
49.3
-0.19
0.47
34
Goethite
37.2
42.7
-0.06
0.42
32
Ferrihydrite
Fe
3+
-
-
0.67
0.41
7
doublet (Fh)
C1 15K
C1 4K
-10-8-6-4-2 0 2 4 6 810
Velocity (mm/s)
-10-8-6-4-2 0 2 4 6 810
Velocity (mm/s)
Fig. 3.40
Mössbauer spectra of C1 at 4 and 15 K
80
Bt2
A1
A2
B1
Bt1
Bt3
70
Goethite
60
50
40
30
Hematite
20
10
Ferrihydrite
0
0
20
40
60
80
100
120
140
160
180
Depth (cm)
Fig. 3.41 Evolution of the relative spectral areas representing Fe in the different iron-bearing
components as a function of depth
Figure
3.42
a represents the full RT spectrum of one of the soil samples from
Cameroun, which were investigated by MS in the framework of a soil mapping
project.
The
spectrum
shows
the
typical
hematite
sextet
together
with
the
