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

Feifei Chen,Xiufeng Cheng,Fapeng Yu,Chao Jiang,Xian Zhao

doi:10.3390/app11167374

Abstract

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 ε11T/ε0 and ε33T/ε0 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.

Highlights

Lithium niobate crystals (LiNbO3, LN) are a type of famous multifunctional materials which have excellent piezoelectric, nonlinear, photorefractive, electro-optical, acousto-optic and pyroelectric properties [1,2,3,4,5,6,7,8]
It is reported that LN crystals have large piezoelectric coefficients, measuring
The piezoelectric coefficients, electromechanical coupling factors, mechanical quality factors and the Curie temperature are the main performance parameters needed to measure the performance of the single crystal transducers, which have an effect on sensitivity, efficiency, timing and temperature stability, etc

Summary

Introduction

Lithium niobate crystals (LiNbO3 , LN) are a type of famous multifunctional materials which have excellent piezoelectric, nonlinear, photorefractive, electro-optical, acousto-optic and pyroelectric properties [1,2,3,4,5,6,7,8]. Based on these properties, LN crystals are widely used in acoustic wave transducers, acoustic filters, acoustic delay lines, electro-optical Q-switches, optical amplitude modulators and so on [9,10,11,12,13,14]. To conduct a complete investigation of the electro-elastic properties of LN crystals and be able to extensively use LN crystals in a wider temperature range, the electro-elastic properties, including the dielectric permittivities, elastic compliances, electromechanical coupling factors and piezoelectric coefficients, were measured and determined by using the impedance method from −150 ◦ C to 150 ◦ C

Experimental Section

Temperature Dependence of Dielectric Permittivity

Temperature Dependence of Elastic Compliance

Conclusions