A new method of growth ferroelectrics crystal

Abstract

Abstract TGS crystals were grown from solution with ethyl alcohol additions. The TGS crystals weighed more than 100 grams. Ferroelectric hysteresis loop, dielectric and pyroelectric properties have been measured. The Curie temperature is 50.2°C. It is found that the properties of TGS grown by this method are similar to that grown by slowly lowering the temperature at constant supersaturation. An infrared detactor constructed with TGS crystal has a detectivity D* (500 K, 25, 1) = 1 × 10* cm CPS½/W, comparable to crystals grown by other methods. Ferroelectric domain patterns will also be described. Generally TGS crystals are grown by reducing temperature or by vaporization at constant temperature. We have developed a new method based on adding alcohol to TGS solution. The alcohol dissolves into water infinitely, but TGS solute does not dissolve into alcohol. This is the foundation of the new method. If we mix alcohol in an aqueous solution of TGS, part of the water in the solution associates with alcohol, concentrating the solution. Thus the supersaturation can be controlled to a certain degree, making it easier to grow TGS crystals. Because this method was developed in Kunming, China, it is called Kunming method. By mixing pure alcohol into the solution, on the one hand, it acts as a concentrating agent. On the other hand, it also acts as a purgative agent (or cleanser). TGS is an organic crystal, and alcohol dissolves many organic impurities produced in the process of crystal growth. As a result, it is easier to grow single crystals of excellent quality.