Geoscience Reference
In-Depth Information
from the growth solutions as OH 2 , the O 2 2 being incorporated in the SiO 2 lattice.
In thermodynamical conditions, different cations (in particular Li 1 ) can be in the
interstitial positions, in particular for compensating the Si 4 1 !
M 3 1 cationic substi-
-SiO 2 lattice. Figure 5.12 shows the effect of growth rate on Al 3 1
concentration in the Z-region of grown crystals using a hydroxide mineralizer [47] .
Aluminum concentration was determined by EPR [18] . Similarly, Laudise [48a,b]
has studied the dependence of the effective partition coefficient for OH 2 impurity
in quartz on growth rate ( Figure 5.13 ). Lithium salt is added to the solvent to check
the aluminum concentration in the grown crystal. The entry of Al occurs in the use
of (OH) and (CO 3 ) based mineralizers. Table 5.3 gives the distribution of impuri-
ties in different sectors of synthetic quartz, which has been studied by Yoshimura
et al. (1979) [49] , and Iwasaki and Kurashige (1978) [50] .
tution into the
α
Figure 5.13 Effective partition
coefficient for OH 2 impurity in quartz
on the growth rate [48a,b] .
350 °
50
375 °
0.1
10
50
100 mil/day
Log R
Table 5.3 Impurities in Synthetic Quartz Crystals (ppm)
Sector
Al
Na
Li
Z
5
1
0.5
1 X
31
9
5
2 X
122
40
5
S
85
26
16
Search WWH ::




Custom Search