Chemistry Reference
In-Depth Information
1.00
0.98
0.96
10K 8T
0.94
-10
-5
0
5
10
V [mm/s]
Fig. 4.9 Mössbauer spectrum recorded at 10 K on 6 nm Co ferrite nanoparticles prepared by
thermal decomposition route submitted to an external of 8T applied parallel to the c-beam [
73
]
A
B
15
A
B
15
10
5
10
0
40
48
56
64
B
eff
(T)
A
B
15
5
10
5
0
48
52
56
B
hf
(T)
0
0
30
60
90
ϑ
(°)
Fig. 4.10 Distributions of the effective magnetic field (left upper), of canting angles (left down),
and of the hyperfine magnetic field (right) for both A and B sites [
73
]
In the case of nanocomposite materials which consist of iron-based alloys
mixed with spinel oxide, the main relevant questions are concerned by the exact
chemical composition of each of the constituents, i.e. both the metallic and the
oxide phases. It has been proposed a strategy combining X-ray diffraction, thermal
gravimetric and magnetic measurements, zero-field and in-field
57
Fe Mössbauer
Fe
p
Co
1
p
spectrometry in the case of
Co
x
Fe
3
x
t
Vac
t
O
ð Þ
composite materials
where a, p, x and t represent the total metal content, p the Fe and Co metallic
content, x the Co
2+
content in the spinel phase and t the vacancies content,
respectively [
88
]. The mean lattice parameters can be estimated by X-ray dif-
fraction, and their values allow thus both the metal composition and the vacancies
a
