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Material Design of New Piezoelectric Crystal Langasite based on the Crystal Structure

基于晶体结构的新型压电晶体硅酸镁石材料设计

基本信息

批准号：
13650738
负责人：
OHSATO Hitoshi
金额：
$ 2.5万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650738/
关键词：
piezoelectricity SAW filter crystal structure analysis langasite high pressure 単結晶

项目摘要

Structures of the piezoelectricity Langasite (La_3Ga_5SiO_<14>) single crystals for wide band SAW filter were analyzed by X-ray single crystal diffractmeter. In this physical year, experiments under the high pressure and the high electric field have been performed at Tohoku University Mechanism of piezoelectricity on the langasite crystal has been clarified.The La_3Ga_5SiO_<14> (LGS) and Nd_3Ga_5SiO_<14> (NGS) were grown by Czochralski method. The crystal structure of langasite putting in diamond anvil cell (DAC) with high pressure (3.3 and 7.4 GPa) was analyzed by 4-axis single crystal diffract meter. The pressure was measured by the ruby fluorescence technique.It was clarified that the linear compressibility of a-direction is greater than that of c-direction under the high pressure. This anisotropy of deformation anticipated by the experiments under the normal pressure performed in the last physical year was confirmed by high pressure experimental. For the confirmation of the compres … More sibility on the a_1-a_2 plane of langasite structure, volumes and deformation of polyhedra with cations are calculated based on the crystal structure data obtained. Specific ionic deformation on the La and Ga polyhedral sites under the high pressure has been found. It was confirmed that mechanism of piezoelectricity on the langasite is due to cation displacement (that is the destruction of charge balance) along [100] based on the volume change and deformation of the La and Ga polyhedral sites. Along this [100] direction, piezoelectricity has been observed practically For the confirmation of the inverse piezoelectricity (electrostriction) under the electric-magnetic field, crystal structure analysis was performed but the crystal structural difference was not observed because of discharge on the surface of small spherical crystal.In summary, mechanism of piezoelectricity of ferroelectric langasite with electric balance was clarified along [100] based on crystal structural deformation under the high pressure. Less

本文<14>用X射线单晶衍射仪分析了用于宽带声表面波滤波器的La_3Ga_5SiO_2压电单晶的结构。在本物理年度内，东北大学进行了高压和高电场下的实验，阐明了硅酸镓镧晶体的压电机理，并采用提拉法生长了La_3Ga_5SiO_<14>（LGS）和Nd_3Ga_5SiO_<14>（NGS）晶体。用四轴单晶衍射仪分析了高压（3.3和7.4GPa）金刚石对顶砧（DAC）中硅酸镧镓的晶体结构。用红宝石荧光技术测量了压力，发现高压下a方向的线性压缩系数大于c方向的线性压缩系数。上一物理年常压实验所预测的这种变形各向异性得到了高压实验的证实。为确认压缩 ...更多信息在硅酸镓镧结构的a_1-a_2平面上的稳定性，计算了含阳离子多面体的体积和形变。发现了高压下La和Ga多面体位上特定的离子形变，根据La和Ga多面体位的体积变化和形变，证实了硅酸镓镧的压电机理是阳离子沿沿着[100]方向的位移（即电荷平衡的破坏）。在沿着[100]方向上，实际上观察到了压电性，证实了逆压电性在电磁场作用下的电致伸缩（电致伸缩），进行晶体结构分析，但是由于在小球形晶体的表面上的放电，没有观察到晶体结构差异。根据高压下晶体结构的变形，阐明了电平衡铁电硅酸镧镧系矿的压电性机理，沿着[100]。少