Name: | LGS Piezoelectric Crystals | Thickness: | 0.13~0.5 Mm |
---|---|---|---|
Second Reference Flat: | 8.0 Mm | Orientation: | Following Customer Specifications |
High Light: | lithium niobate wafer,yttrium calcium oxy borate |
LGS Piezoelectric Crystals
Langastie crystal (La3Ga5SiO14, LGS), belonging to the space group P321, point group 32, has been reported to be promising new piezoelectric materials for fabrication of surface acoustic wave (SAW), bulk acoustic wave (BAW) devices and sensors(pressure sensor, acceleration sensor, QCM,etc.). It is reported that devices made of langasite crystal could be used at a high temperature up to 900C because of its high thermal stability.
Basic Properties
Langasite crystal possesses some great properties, such as higher electromechanical coupling factor than quartz, no phase transition from room temperature to melt point. Some properties of langasite crystal are shown in Table 1 and Table 2.
With the rapid development of the communication technology, the new generation communication system enables people not only to talk, but also to transmit image, data and video. Langasite crystal possesses high SAW properties compared with quartz, which make it to be the most competitive material in this field. SAW properties of langasite and quartz are listed in the Table 3.
Products Information
Diameter |
10~100 mm |
Thickness |
0.13~0.5 mm |
First Reference Flat |
15.0 mm |
Second Reference Flat |
8.0 mm |
Surface Roughness |
Ra≤1 nm |
Orientation |
following customer specifications |
Other sizes reflected in customer specifications |
Table 1 Dielectric, piezoelectric, elastic stiffness constants and their first order temperature coefficients of langasite crystal
Constant |
Relative |
Piezoelectric Constant |
Elastic Stiffness(1011 Pa) |
|||||||
11 |
33 |
d11 |
d14 |
c11 |
c12 |
c13 |
c14 |
C33 |
C44 |
|
Value |
18.96 |
50.19 |
5.66 |
-5.48 |
1.898 |
1.058 |
1.022 |
0.144 |
2.626 |
0.535 |
First Order Temp. Coef.(10-6K-1) |
150 |
-760 |
329 |
-342 |
-66 |
204 |
-75 |
-335 |
-94 |
-63 |
Table 2 Comparative properties of piezoelectric crystals
Properties Crystal |
Quartz SiO2 |
Langasite |
Lithium tetraborate Li2B4O7 |
Lithium tantalate LiTaO3 |
Electromechanical Coupling Factor K, %(BAW) |
7.0 |
15.8 |
24.0 |
47.0 |
Frequency Spacing f, % |
0.25 |
0.90 |
4.00 |
7.00 |
Q-Factor Q, ×103 |
100 |
50 |
10 |
2 |
Temperature Frequency Coefficient |
0.5 |
1.6 |
6.0 |
4.0 |
Table 3 SAW properties of langasite and Quartz
Properties Crystal |
Quartz (SiO2) |
Langasite (La3Ga5SiO14) |
Density, g/cm |
2.65 |
5.746 |
SAW Velocity Vef, m/s |
(0°, 132.75°, 0°) |