Near-stoichiometric Lithium Niobate Crystal Growth And Nature Study

Lithium niobate (LN) is a quality multi-functional crystal, it has good piezo-electric, nonlinear-optic, electro-optic and photorefractive properties. Lithium Niobate could be grown by Czochralski method. It has perfect thermal, chemical and mechanical stabilizations. Based on the above merits, Lithium niobate is widely used to fabricate a number of devices such as electro-optics elements, piezoelectric drivers and detectors, and surface acoustic wave filters. It is also targeted as a key material for use in optical switches, modulators and SHG ( second harmonic generation ) devices.Lithium niobate is a typical non-stoichiometry crystal. The deficiency of lithium ion makes it have a lot of vacancies, this makes it lost many good physical properties. The recent research shows that, while the content of lithium element increased in LN crystal, the performance of the crystal increased a lot. Due to such background, we hope to grow near-stoichiometric Lithium niobate crystal (NSLN) with low vacancy density. In recent years, NSLN crystal has attracted much attention. In this work, we do some systematic research on the growth,, structure, defect and physical properties of NSLN crystal, it mainly include such aspects:1. Crystal growthNear-stoichiometric lithium niobate crystals with a diameter of two inches have been grown in a suspend quazi double-crucible by Czochralski method with continuous powder supply system. Because the crystals are grown with suitable technological parameters, they have perfective quality.Since crystal growth is a complex physical-chemical process, the affect qualities of crystals during the growth were analyzed, according to the theories of thermodynamics and dynamics. Based on this, we find some...