Piezoelectric Langasite La₃Ga₅SiO₁₄ (LGSO) Crystal

Product Name: Piezoelectric Langasite La3Ga5SiO14 (LGSO) Crystal

Langasite La₃Ga₅SiO₁₄ crystals (LGSO or LGS), also known as Lanthanum gallium silicate, has its crystal structure belonging to the space group P321, point group 32. LGS is a promising piezoelectric material with no phase transitions up to its melting point of 1470 °C. LGSO has the value of electromechanical coupling coefficient, which is between that of a quartz crystal and that of lithium tantalate crystal. LGSO is mainly applied in fabrication of SAW (surface acoustic wave), BAW (bulk acoustic wave) devices and sensors (pressure sensor, acceleration sensor. etc.).

A list of the main applications of LGSO (LGS) include:

• High Temperature SAW sensors
• High Temperature BAW sensor
• High Temperature and High-Sensitivity piezo-static sensor elements
• Crystal units as BAW resonators with high motional capacitance
• SAW devices for frequency control and selection
• Wideband piezoelectric filters, both discrete and monolithic

Diameter: 10 - 60 mm, or can be customized

Thickness: 0.25-0.5 mm, or can be customized

Total Thickness Variation (TTV) for a 2" Wafer: < 10um

First Reference Flat: 15.0 mm

Second Reference Flat: 8.0 mm

Surface Roughness (Polished): Ra ≤ 1 nm

Surface Polish Choices: SSP or DSP.

Orientations: Euler angles (0°,138.5°,26.7°) or (0°,22°,90°), or Z-cut, or following customer specifications. Definition of Euler angles (0,138.5,26.6): 42.5 degree rotated Y-cut with reference flat perpendicular to 26.6 degree rotated X axis

Lead time: 6-8 weeks

Table 1 Dielectric, piezoelectric, elastic stiffness constants and their first order temperature coefficients of Langasite crystal

Table 2 Comparative properties of piezoelectric crystals

Table 3 SAW properties of Langasite and Quartz