Geoscience Reference
In-Depth Information
Table 7.31 Experimental Conditions for the Growth of LiH 2 B 5 O 9 Crystals [356]
No. Nutrient
Composition
Temperature
( C)
Pressure
(bar)
%
Fill
Duration
(days)
Size
(mm)
Remarks
1 4
1.
LiBO 2 —2.0
250
100
60
7
Transparent
crystals
B 2 O 3 —4.0
HCOOH
(1.5 M)—
6ml
2.
LiBO 2 —2.0
250
90
55
7
1
3
Transparent
crystals
B 2 O 3 —4.0
HCOOH
(1.5 M)—
5ml
3.
LiBO 2 —2.0
250
110
65
7
5
Massive
crystals
B 2 O 3 —4.0
HCOOH
(1.5 M)—
7ml
4.
LiBO 2 —2.0
250
100
60
7
0.5 1 Small
transparent
crystals
B 2 O 3 —4.0
HCOOH (2 M)
—6 ml
5.
LiBO 2 —2.0
250
100
60
8
0.5
Small
transparent
crystals
B 2 O 3 —4.0
HCOOH (3 M)
—6 ml
6.
LiBO 2 —2.2
250
100
65
7
1 3
Transparent
crystals
B 2 O 3 —4.0
HCOOH
(1.5 M)—
6ml
superionic. Also, they possess good thermal and chemical stability. Owing to the
possibility of wide isomorphous substitutions, one can consider these borates as
polyfunctional materials with device potential. However, borates of hydrothermal
origin are being used essentially as piezoelectric, ferroelectric, and superionic
borates.
Li 2 B 4 O 7 is known as a Li superionic conductor with its ionic conductivity of the
order of 10 2 4 W 2 1 cm 2 1 at about 500 K and has a large piezoelectric constant.
A combination of piezoelectric and superionic properties should give rise to electro-
acoustic anomalies in Li 2 B 4 O 7 crystals. The complex impedance spectroscopic (CIS)
studies reveal the physical nature of the acousto-ionic interaction and also on the char-
acteristics of ion transport in solid electrolytes on the whole. Li 2 B 4 O 7 maybeusedas
a dielectric resonator at about 10 MHz. The noise observed in the CIS data for
Li 2 B 4 O 7 is not a thermal noise, but it appears to be 1/f quantum noise [371] .
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