Geoscience Reference
In-Depth Information
BaO
a
Al
2
O
3
a
H
2
O,
SrO
a
SiO
2
a
H
2
O, K
2
O
a
SiO
2
a
H
2
O, Na
2
O
a
SiO
2
a
H
2
O,
CaO
H
2
O, and so on. More
accurate phase equilibria data were obtained for the earlier studied systems. At this
time, many laboratories in the erstwhile Soviet Union attained a special prominence
which led to the rapid growth of this branch of science not only in terms of laborato-
ries but also in terms of research personnel.
At one time, in the erstwhile Soviet Union there were more than 1000 research-
ers in this field. During the 1960s, an intensive study of the hydrothermal process
of synthesis and growth of single crystals which did not have the analogues in
nature began. During the 1970s, there was a quest for the search and the growth of
hitherto unknown compounds of photosemiconductors, ferromagnets, lasers, piezo-
electrics, and ferroelectrics and, in this regard, hydrothermal technology attracted a
great attention. Many other nations, including China and India, got into the field of
hydrothermal growth of crystals. Several established laboratories in the world
began to study systematically various aspects of the hydrothermal growth of crys-
tals such as the physicochemical principles, kinetics, designing new apparatus, and
growing new compounds. This marks a significant change in the trend of hydro-
thermal research. Specific aspects of the hydrothermal method as a modeling tool
a
SiO
2
a
H
2
O, CaO
a
Al
2
O
3
a
H
2
O, CaO
a
Al
2
O
3
a
SiO
2
a
Figure 2.11 Growth of
quartz crystals in the world's
largest autoclave.
Source: Photograph courtesy
of Dr. Taki.
