Class-1 piezoelectric monocrystal and growing method thereof

Abstract

The invention relates to a novel piezoelectric single crystal and a crucible-down growing method thereof. It is characterized in that: the piezoelectric crystal formed by substituting elements of the same group has a general formula of Sr3-xMexNbGa3Si2O14, wherein Me is Ca or Ba, x=0.1-2.9; priority is 0.1≤x≤1.5, and the growth method is based on Sr3 -xMexNbGa3Si2O14 stoichiometric ratio ingredients, mixed evenly, pre-fired at 1150-1170°C for 8-12 hours, through solid-state reaction, polycrystalline raw materials were synthesized; Put it in the descending method growth furnace, melt the raw material and the top of the seed crystal at a temperature range of 1450-1480°C, maintain the temperature gradient at the growth interface at 20-40°C / cm, and the crucible descending speed is less than 3mm / h. Piezoelectric single crystals of different directions, shapes and sizes can be grown according to needs. It has the advantages of simple process equipment, convenient operation, and multi-yield in one furnace. It is suitable for the growth or production of industrial-scale crystals.

Description

technical field [0001] The present invention relates to a kind of piezoelectric single crystal and its growth method, more precisely, it replaces Sr with the same group elements 3 NbGa 3 Si 2 o 14 (SNGS) Sr in a single crystal to form a series of mixed piezoelectric crystals with the general formula Sr 3-x Me x NbGa 3 Si 2 o 14 , where Me is Ca or Ba, and x is between 0.1-2.9. The crystals were grown by the crucible drop method. It belongs to the field of single crystal growth. Background technique [0002] Lanthanum Gallium Silicate La 3 Ga 5 SiO 14 (langasite: LGS) series piezoelectric single crystals are a series of new piezoelectric materials discovered in the mid-1990s. They have many advantages in the application of surface acoustic waves and bulk waves. Therefore, LGS series crystals quickly become widely concerned in the piezoelectric field. Object. A variety of new materials with langasite structure and excellent piezoelectric properties have been succ...

AI Technical Summary

Problems solved by technology

At present, the pulling method is widely used in the world to grow LGS series piezoelectric crystals. When the LGS series crystals are grown by the pulling method, due to the characteristics of the facet growth of this type of crystal, bulk defects are prone to occur, which seriously affects the quality and yield of the crystal; At the same time, the crystals grown by the pulling method are often hexagonal, and they need to be rounded to be processed into wafers for acoustic surface applications, which not only increases the workload, but also wastes expensive raw materials (Uda S, Wang SQ, Konishi N, Inaba H , Harada J, Growth habits of 3and 4-inch langasite single crystals, Journal of Crystal Growth237-239(2002)707-713)