Growth,Structure and Characteristic of Langasite Single Crystals

• Main Authors: CHIN CHEN WEN, 陳敬文
• Other Authors: 洪正聰
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/04247219812279177897

碩士 === 中華技術學院 === 電子工程研究所碩士班 === 95 === In this research paper, we use Russian VNIISIMS Corporation's Kristall-3M crystal grower, designed with Czochralski Method , and a high quality of La3Ga5SiO14 (LGS) single crystal has been made first at Taiwan. The LGS compound has high piezoelectric coupling coefficient , temperature compensation and low acoustic loss. In the process of crystal growing, we filled the argon and 3% oxygen. The rotational speed of pulling rod is 6 rpm, and the crystal grow with the speed 2.1 ~ 2.6 mm/hr. The length of ingot is 85 mm, and it’s diameter is 35 mm, it’s weight is 540 g. We use X-ray powder diffraction and the Raman scattering to find some characteristic of the crystal. As Compared with X diffraction's data (ICDD), it shows that the crystal structure is effected obviously by heat field condition, growth rate and annealing. The Raman spectrum obtained from the [0001] direction shows that the LGS single crystal exist some dislocation. Keywords：Czochralski Method , Langasite