Investigation of Electro-Elastic Properties for LN Single Crystals at Low Temperature.

Lithium niobate crystals (LiNbO₃, LN) are multifunctional crystal materials with many outstanding properties. In this work, the electro-elastic properties of LN single crystals were explored at temperatures from −150 °C to 150 °C. The temperature dependences of dielectric permittivities, elastic compliances, electromechanical coupling factors and piezoelectric coefficients were determined using the impedance method. The LN crystals possessed large dielectric permittivities, the ε 11 T / ε 0 and ε 33 T / ε 0 were 83.2 and 29.4 at room temperature, respectively. The elastic compliances s₁₁, s₁₃, s₃₃ and s₄₄ presented a positive increase as the temperature increased, and the variations were 5.0%, 8.2%, 4.6% and 5.4%, respectively, showing a good temperature stability. Moreover, the temperature dependence of the electromechanical coupling factors and piezoelectric coefficients for different vibration modes were studied with a temperature range from −150 °C to 150 °C, where the thickness shear vibration mode d₁₅ presented a large piezoelectric response and minimal temperature variation. [ABSTRACT FROM AUTHOR]