LGS

Langasite - Lanthanum Gallium Silicate, is a piezoelectric crystal of gallogermanate family, having 32- symmetry class and described by the chemical formula: La3Ga5SiO14. Method for the production - the Czochralski method. It is used in the production of wafers for surface acoustic waves devices, direct piezoelectric effect sensors bulk acoustic waves devices. Due to the absence of pyroelectric effect, hysteresis of properties, the absence of a phase transition up to the melting temperature (1470°C) and the presence of temperature compensated cuts, Langasite is used where the temperature dependence of electrical signal is important.

  Characteristic Value Measurement units
1. Hygroscopic property N/A -
2. Hysteresis effect N/A -
3. Dielectric capacity ε11 = 19;
ε33 = 50
-
4. Q-factor 50000 -
5. Symmetry class 32 -
6. Thermal-expansion coefficient α11 = 5.630;
α33 = 4.079
mкK -1
7. EMC coefficient (BAW) 15.8 %
8. EMC coefficient (SAW) 0.34 (0°;138,5°;26,7°) %
9. Cell parameters a = 8.170x10-10;
c = 5.098x10-10
 m
10. Density 5.74 g/cm 3
11. Pyroelectric effect N/A -
12. Piezoelectric modulus d12 = 6.1;
d14 = 5.4
pC/N
13. Resonance spacing 0.9 %
14. SAW velocity 2723 (0°;138,5°;26,7°) m/s
15. Mohs hardness 6.6 -
16. Debye temperature 742 K
17. Curie temperature N/A оС
18. Melting temperature 1480 оС
19. Temperature Frequency Coefficient 1.6х10-5 °C-1
20. Resistivity >1х1012 (25°C) ohm*cm