Geoscience Reference
In-Depth Information
Figure 5.30 Yield of GaPO
4
single crystals as a
function of time
[129]
.
0.
m
(g)
0.3
0.2
0.1
2
46 8
τ
(days)
Solubility (mol l
1
2.5
160
°
C
2
180
°
C
1.5
200
°
C
1
250
°
C
0.5
% H
2
SO
4
0
0
20
40
60
80
100
Figure 5.31 Solubility of GaPO
4
in the phospho-sulfuric acid solution 15 M H
3
PO
4
1
9M
H
2
SO
4
[122]
.
Source: Courtesy of the Gauthier-Villars/ESME, Paris.
Table 5.11 Crystallization Kinetics for GaPO
4
Solvent HCl
HNO
3
KF
NaOH
T (
C)
200
250
300
200
250
300
200
250
300
200
250
300
K
0.22
0.48
0.76
0.11
0.28
0.41
0.09
0.14
0.26
0.04
0.05
0.15
N
0.61
0.58
0.57
0.58
0.50
0.47
0.20
0.22
0.18
0.30
0.28
0.27
5.4.2 Morphology
The morphology of the GaPO
4
sin
gl
e cryst
a
ls is s
ho
wn in
F
igure 5.32 [117]
.The
commonly appearing faces are
Figure 5.33
shows
the characteristic photographs of GaPO
4
crystals obtained by hydrothermal
method. The growth rates along various crystallographic directions decrease in the
following sequence:
½
1011
; ½
0111
; ½
1010
; ½
1012
: