Piezoelectric Properties Of Single Crystals Research Articles

Aspects of symmetry of Electromechanical Coupling Factors in Piezoelectric Single Crystals

This paper presents the method for the calculation of anisotropic piezoelectric properties of single crystals and the graphical display of the results in 3 D. Crystallographic preferred orientations were determined for piezoelectric modules and electromechanical coupling factor, which measures the ability of a material to interconvert electrical and mechanical energy.

압전 PMN-PZT 단결정의 유전 및 압전 특성에 미치는 전극 종류의 영향

The effect of the electrode type on the dielectric and piezoelectric properties of Pb(Mg 1/3 Nb 2/3 )O₃-PbZrO₃-PbTiO₃ (PMN-PZT) single crystals was investigated in an effort to improve their properties for various piezoelectric applications. First, three different types of PMN-PZT single crystals [PMN-PZT-A (piezoelectrically soft type; dielectric constant ~ 10,000), PMN-PZT-B (piezoelectrically soft type; phase-transition temperature between the rhombohedral and tetragonal phases (T RT ) ~ 145℃), PMN-PZT-C (piezoelectrically hard type; high mechanical quality factor (Q m ) ~ 1,000)] were fabricated using the solid-state single crystal growth (SSCG) method. Then, four different types of electrodes [sputtered Au, sputtered Cr/Au, sputtered Ti/Au, and fired Ag] were formed on the single crystals, and their dielectric and piezoelectric properties were measured. The single crystals with a sputtered Ti/Au electrode showed the highest dielectric and piezoelectric constants but the lowest coercive electric field (E C ). The single crystals with a fired Ag electrode showed the lowest dielectric and piezoelectric constants but the highest coercive electric field (E C ). This dependence on the type of electrode was most significant in the piezoelectrically hard PMN-PZT-C single crystals. However, the effects of the electrode type on the phase transition temperatures (T C , T RT ) and dielectric loss were negligible. These results clearly demonstrate that it is important to select an appropriate electrode so as to maximize the dielectric and piezoelectric properties of single crystals in each type of piezoelectric application.

Calculating anisotropic piezoelectric properties from texture data using the MTEX open source package

AbstractThis paper presents the background for the calculation of anisotropic piezoelectric properties of single crystals and the graphical display of the results in two or three dimensions, and the calculation of the aggregate properties from constituent crystals and the texture of the aggregate in a coherent manner. The texture data can be obtained from a wide range of sources, including pole figure diffraction and single orientation measurements (electron backscattered diffraction, electron channelling pattern, Laue Pattern, optical microscope universal-stage). We consider the elastic wave propagation in piezoelectric crystals as an example of the interaction of electrical (2nd rank tensor), piezoelectric (3rd rank tensor) and elastic properties (4th rank tensor). In particular, we give explicit formulae for the calculation of the Voigt averaged tensor from individual orientations or from an orientation distribution function. For the latter we consider numerical integration and an approach based on the expansion into spherical harmonics. We illustrate the methods using single crystals, polycrystalline quartz measured using electron channelling patterns and ideal Curie limiting groups applied to quartz aggregates. This paper also serves as a reference paper for the mathematical tensor capabilities of the texture analysis softwareMTEX.

Luminescence properties of piezoelectric single crystals with langasite structure

Luminescence properties of single crystals of langasite (LGS), langataite (LGT), and langanite (LGN) are investigated at 5 K by using synchrotron radiation as an exciting light source. Two emission bands are observed at 420 and 500 nm in LGS, at 410 and 460 nm in LGT, and at 500 and 535 nm in LGN. The origin of these bands is discussed by reference to the electronic structure of LGS.

Enhanced Piezoelectric Properties of Piezoelectric Single Crystals by Domain Engineering

Various engineered domain configurations were induced into barium titanate (BaTiO 3 ) single crystals, and their piezoelectric properties were investigated as a function of (1) the crystal structure, (2) the crystallographic orientation and (3) the domain size. As a result, the orthorhombic mm2 BaTiO 3 crystals showed the highest piezoelectric properties among three kinds of BaTiO 3 crystals such as tettagonal 4mm, orthorhombic mm2 and rhombohedral 3m phases. On the other hand, the [001] c oriented BaTiO 3 crystals always exhibited the larger piezoelectric properties than the [111] c oriented BaTiO 3 crystals. Moreover, the domain size dependence on the piezoelectric properties was discussed, and this result revealed that the piezoelectric property was strongly dependent on the domain size, i.e., the piezoelectric properties significantly increased with decreasing domain size. On the basis of the above results, the most suitable engineered domain configuration was proposed for the high-strain high-coupling piezoelectric application.

Enhanced Piezoelectric Properties of Piezoelectric Single Crystals by Domain Engineering

ABSTRACTFor tetragonal barium titanate (BaTiO3) single crystals, an electric field (E-field) applied along [111]c direction can induce an engineered domain configuration. In this study, the engineered domain structures with different domain sizes were induced into BaTiO3 single crystals, and their piezoelectric properties were investigated as a function of a domain size. Prior to this study, the dependence of domain configuration on the temperature and the E-field was investigated using a polarizing microscope in order to understand the optimum condition for fine and coarse domain structures. As a result, above Curie temperature (Tc) of 132.2 °C, when the E-field over 6 kV/cm was applied along [111]c direction, the engineered domain configuration with fine domain structure appeared. Moreover, it was also found that this fine domain structure was still stable at room temperature without E-field. On the other hand, the coarse domain structure was obtained by poling at just below Tc. Finally, the piezoelectric properties were measured using the 31 resonators with different kinds of domain sizes. As the result, it was found that the piezoelectric properties such as d31 and k31 increased significantly with decreasing domain sizes.

LINE-FOCUS-BEAM ACOUSTIC MICROSCOPY AND ITS APPLICATION TO CHARACTERIZATION OF PIEZOELECTRIC SINGLE CRYSTALS

Abstract Line-focus-beam (LFB) acoustic microscopy with high measurement accuracy, applicable to quantitative characterization of electronic device materials, has been developed and this paper is a brief review of the method and system. The application to quantitative evaluation of elastic properties of piezoelectric single crystals of LiNbO3, and LiTaO3, focusing on the subjects of the elastic inhomogeneity and the congruent chemical composition. which present serious problems during the mass production in industry, is described to demonstrate the usefulness as a new analytical technique.

Elastic and piezoelectric properties of paratellurite (TeO 2)

The elastic and piezoelectric properties of single crystals of paratellurite (TeO 2) are investigated. In the <110 > direction, shear waves may propagate with the extremely low phase velocity of 0.6 × 10 3 m s −1. The coupling coefficient for shear waves in the <001 > direction is of the order of 10%. Direct excitation of torsional vibrations is possible using a very simple electrode configuration. There are certain directions in which the phase velocity of shear waves is independent of temperature.