New AィイD23ィエD2BCィイD23ィエD2DィイD22ィエD2OィイD214ィエD2-type single crystal materials for piezoelectric applications

最近在电子技术方面的进展要求新的压电晶体具有这样的超性能，如零温度系数和较大的机电耦合因子。We have？ed a series of new leading candidates to satisfy those？ments： LaイイD23イD25イD214イD2 （Langasite， LGS）、LaイD23イD2NbイD20. 5イD25. 5イD20. 5イD20. 5イD2 （LTG）。Since LGS-type structure has 4 kinds of sites （A型D23型D2 BC型D22型D2 O型D214型D2）， it has high potential for creation of new material with better properties。由不同的替代品，一系列的LGS-type晶体已被合成。The Determination of Latice Constants for the Crystals展示了一个增量的晶格常数对压电调制的增量具有优势。特别地，增加了A站点中的平均电离辐射，是有效的。根据这种趋势，新的材料已经被合成了 ... More d由两种不同的变体组成，一种是A站点的变体，另一种是所有A-、B-、C-和D站点。这些材料的晶体是由微拉式技术测试的。Among them， transparent La D23-x D2SrD2x D2Ta D20.5+x/2 Ga D25.5-x/2 D2O D214 D2and SrD23 TaGa D23 D2Si D214 D2O D214 D2ro single crystals without crack？were grown。其次，这些材料的单晶体在1英寸的直径上也是由Czochralski技术生长的，其脉冲速率为0.6毫米/小时。这些晶体与生长轴有关的晶格常数和化学成分的明显变异是不被观察到的。他们展示了与LGS、LNG和LTG比较的超级压电性能。使用LGS单晶体，我们制造了单晶体过滤器（10.4和21.4 MHz），具有低输入和输出影响、小尺寸和低干扰，并与四重奏制造的性能进行了比较。A71 MHz宽宽带SMD滤波器也为GSM基站制造和展示了高级属性。一个71 MHz LGS滤波器的体积是1/5，是一种由石英制成的传统离散型。Less（低）

Recent progress in electronic technology requires new piezoelectric crystals having superior properties such as zero temperature coefficients and large electromechanical coupling factors. We have developed a series of new leading candidates to satisfy those requirements : LaィイD23ィエD2GaィイD25ィエD2SiOィイD214ィエD2 (Langasite, LGS), LaィイD23ィエD2NbィイD20.5ィエD2GaィイD25.5ィエD2OィイD214ィエD2 (LNG) and LaィイD23ィエD2TaィイD20.5ィエD2GaィイD25.5ィエD2OィイD214ィエD2 (LTG). Since LGS-type structure has 4 kinds of sites (AィイD23ィエD2BCィイD23ィエD2DィイD22ィエD2OィイD214ィエD2), it has high potential for creation of new materials with better properties. By isovalent substitution, a series of LGS-type crystals have been synthesized. The determination of lattice constants for these crystals showed that an increase of lattice constants is advantage for the increment of piezoelectric moduli. Especially, and increase of an average ionic radius in A-site was found to be effective. According to this tendency, new materials have been synthesize … More d by two kinds of aliovalent substitutions, one is the substitution with A-site, and the other is that with all A-, B-, C-, D-sites. Crystallinity of these materials was examined by the micro pulling-down technique. Among them, transparent LaィイD23-xィエD2SrィイD2xィエD2TaィイD20.5+x/2ィエD2GaィイD25.5-x/2ィエD2OィイD214ィエD2 and SrィイD23ィエD2TaGaィイD23ィエD2SiィイD22ィエD2OィイD214ィエD2 micro single crystals without crack formation were grown. Subsequently, single crystals of these materials 1 inch in diameter have also been grown by the Czochralski technique, at a pulling rate of 0.6 mm/h. Obvious variation of lattice constants and chemical composition of these crystals along the growth axis was not observed. They showed superior piezoelectric properties comparable to LGS, LNG and LTG.Using LGS single crystals, we made monolithic-type filters (10.4 and 21.4 MHz) with low input and output impedance, small size and with low attenuation, compared with those made of quartz. A 71MHz wide passband SMD filter for the GSM base station was also made and exhibited superior properties. The volume of a 71 MHz LGS filter is 1/5 that of a conventional discrete-type one made of quartz. Less