Geoscience Reference
In-Depth Information
c
B
94
A
82
66
75
A
68
B
56
52
48
44
33
A
B
32
33
25
B
18
A
06
02
Na(2)
b
a
O(1)
3
LaO(2)
3
Na(1)F
Figure 8.7 Structural projection of Na
3
La
2
(CO
3
)
4
F
[22]
.
Source: Courtesy of the Academic Press, Orlando, FL.
have been obtained by the hydrothermal method
[31
35]
. These compounds have
740
C and P
been synthesized by hydrothermal growth at T
200 MPa in 20 h.
The starting materials are usually the carbonates of alkali or alkaline earth, rare
earth, or 3d transition metal fluorides, and alkali fluoride.
Figure 8.7
shows the struc-
tural projection of Na
3
La
2
(CO
3
)
4
F, along Ref.
22
. The structure shows double layers
5
5
