Lithium Tantalate Properties

Fundamental Properties
| Item | ||
|---|---|---|
| Melting Point | 1650° C | |
| Crystal System | Trigonal | |
| Point Group | 3m | |
| Crystal Density | 7.465 x 103 kg / m3 | |
| Curie Temperature (Tc) | 603.5 ± 5.5°C | |
| Heat Capacity (Cp) | 100 J / k.mol | |
| Dielectric Constants | (T11) | 53.6 |
| (T33) | 43.4 | |
| Elastic Constants | (CE11) | 2.331 x 1011 N / m2 |
| (CE12) | 0.464 | |
| (CE13) | 0.852 | |
| (CE14) | -0.161 | |
| (CE33) | 2.761 | |
| (CE44) | 1.029 | |
| Piezoelectric Strain Constants | (e15) | 53.6 |
| (e22) | 1.84 | |
| (e31) | -0.11 | |
| (e33) | 1.93 |
Typical Acoustic Properties
Surface Acoustic Wave Properties
| Description | Propagation | Design | Surface Wave Velocity (m/s) | Coupling Coefficient k² (%) | Group Delay Time Temp Coefficient (ppm/°C) | Propagation Loss of SAW (dB/cm) |
|---|---|---|---|---|---|---|
| 36 ° Y – Cut | X – Axis | SSBW | 4160 | 5.0 | 28 ~ 32 | – |
| 42° Y – Cut | X – Axis | SSBW | 4022 | 7.6 | 40 | – |
| X – Cut | 112.2 Y Direction | SAW | 3290 | 0.75 | 18 | – |
| SAW = Surface Acoustic Wave L, SAW =Leaky SAW | ||||||
Selective Piezoelectric Coupling Factors & Frequency Constants
| Plate Orientation | Wave Type | Coupling Factor | Resonance Frequency Constant (MHz-mm) |
|---|---|---|---|
| X | S | 0.44 | 1.906 |
| Z | E | 0.19 | 3.040 |
| 36° Y – Cut | QE | – | – |
| 163° Y – Cut | QS | – | – |
| E = extensional S = shear QE = quasi – extensional QS = quasi – shear | |||
Typical Optical Properties
Electro-Optic Coefficients r(10-12 mV-1) at 632.8 nm
| rT13 | 8.4 | rS13 | 7 |
| rT22 | – | rS22 | 1 |
| rT33 | 30.5 | rS33 | 30.3 |
| rT51 | – | rS51 | 20 |
Nonlinear Optical Coefficients at 1-06 μ m (*d31=d15)
| d22 / l d36KDP l | 4.4 |
| d31 / l d36KDP l | -2.7 |
| d33 / l d36KDP l | -4.1 |
Refractive Index at 632.8 nm
| no | 2.1787 |
| ne | 2.1821 |
| no: TE mode ne: TM mode | |


