Growth of Piezoelectric Single Crystals and Their Applications to SAW Devices

压电单晶的生长及其在声表面波器件中的应用

基本信息

批准号：
11650330
负责人：
KARAKI Tomoaki
金额：
$ 2.24万
依托单位：
Toyama Prefectural University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650330/
关键词：
langasite single crystal piezoelectric single crystal SAW device Czochralski method single-crystal growth piezoelectric constant SAW propagation property ブリッジマン法粘性

项目摘要

The following results were obtained in this research :(1) The compounds of Ba_3Ga_2Ge_<4-x>Si_xO_14, Ba_3Ga_2Si_<4-x>Sn_xO_14, Ba_3Nb_xGa_<x+2>Si_<4-2x>O_14, Ba_3Ga_2Ge_<4-x>Sn_xO_14 (x > 0.5), Ba_<3-x>Ca_xNbGa_3Si_2O_14 (0 < x < 3) have been regretfully not langasite structures.(2) After permuting the A site by Ba, Ba_3Ga_2Ge_4O_14 (BGG) has the langasaite structure and has large lattice constants. Crystal growth of BGG has been tried, but quality crystal was not achieved. The Bridgman technique might be effective for this material.(3) Single crystal of Ca_3NbGa_3SiO_14 (CNGS), which has the langasite structure, has been successfully grown. But its piezoelectric constant |d11| was about 4x10^<-12> C/N, that smaller than expected by a/c ratio.(4) According to the result of CNGS crystal, the piezoelectric constant d may be proportional to lattice constant a, not be proportional to a/c ratio. The crystal growth method for large lattice materials has to be modified. The Bridgman technique may be effective.(5) All elastic, piezoelectric and dielectric constants, and their first and secondary temperature coefficients of La_3Ga_5SiO_14 (LGS) and La_3Ta_0.5Ga_5.5O_14 (LTG) crystals have been measured.(6) Rayleigh SAW properties of LGS crystal with propagation direction of (0°, 140°, 25°) was simulated ; velocity ν(free) = 2750 m/s, electromechanical coupling factor κ^2 = 0.36 %, temperature coefficient of delay TCD = 0, power flow angle PFA = 2°.(7) Rayleigh SAW properties of LGS crystal with propagation direction of (15°, 151°, 40.5°) was calculated ; ν(free) = 2860 m/s, κ^2 = 0.41 %, TCD = 0, PFA = 0°.(8) The SAW properties of LGS were measured by using SAW filters. The measured results have good agreement with the simulation results.(9) Rayleigh SAW properties of LTG crystal with propagation direction of (13°, 150°, 36°) was simulated ; ν(free) = 2690 m/s, κ^2 = 0.5 %, TCD = 0, PFA = 0°.

在这项研究中获得了以下结果：（1）BA_3GA_2GE_ <4-x> si_xo_14的化合物，BA_3GA_2SI_ <4-x> sn_xo_14，ba_3nb_xxga_ <x+2> 0.5），BA_ <3-X> CA_XNBGA_3SI_2O_14（0 <x <3）已正确地不是langasite结构。（2）在由BA，BA_3GA_2GE_2GE_4O_4O_14（BGG）将A网站定位后，具有Langasaite结构，并且具有较大的Lattice Constant。已经尝试过BGG的晶体生长，但没有实现质量晶体。 Bridgman技术可能对该材料有效。（3）具有Langasite结构的CA_3NBGA_3SIO_14（CNGS）的单晶已成功生长。但是它的压电常数| D11 |约为4x10^<-12> C/N，比A/C比的预期小。（4）根据CNGS晶体的结果，压电常数D可能与晶格常数A成正比，而不是与A/C的比例成比例。必须修改大型晶格材料的晶体生长法。 Bridgman技术可能是有效的。（5）所有弹性，压电和顽固的常数，以及LA_3GA_3GA_5SIO_14（LGS）和LA_3TA_0.5GA_0.5GA_5GA_5.5O_14（LTG）晶体的第一个和二级温度系数。模拟了140°，25°）；速度ν（free）= 2750 m/s，机电耦合因子κ^2 = 0.36％，延迟tcd = 0的温度系数，功率流角pfa = 2°。 ν（free）= 2860 m/s，κ^2 = 0.41％，tcd = 0，pfa = 0°。（8）通过使用锯过滤器测量LGS的锯特性。测得的结果与模拟结果具有良好的一致性。（9）模拟了LTG晶体的瑞利锯特性，其传播方向为（13°，150°，36°）。 ν（free）= 2690 m/s，κ^2 = 0.5％，tcd = 0，pfa = 0°。