Preparation method of growing potassium tantalate-niobate series monocrystal materials by fused mass pulling method

Abstract

The invention discloses a preparation method of growing potassium tantalate-niobate series monocrystal materials by a fused mass pulling method. The invention starts from the preparation of potassium tantalate-niobate polycrystal powder materials. The preparation method comprises the following steps: using K2CO3, Ta2O5 and Nb2O5 as raw materials to obtain KTN polycrystal powder materials through the processes of grinding, uniform mixing, press forming and sintering; then, raising the temperature of the KTN polycrystal powder materials to a temperature near the melting point; continuously raising the temperature after the heat preservation until all raw materials are melted; lowering the temperature to the melting point of the crystal after the constant-temperature overheating; lifting the crystals from the liquid level after the processes such as seeding, neck contraction, shouldering, equal neck steering and equal neck growth; and lowering the temperature to the room temperature to obtain KTN monocrystals. The invention overcomes the defects of high cost, long period and the like of the KTN crystal growth by high-temperature solvents. Under the condition without using the solvent, the fused mass pulling technology is used as the basis, the technical process of the crystal growth is reasonably designed, the stable and repeated growth of large-dimension and high-quality KTN crystals is realized, and the growth period of the crystals can be shortened.

Description

technical field [0001] The invention belongs to the research field of preparation technology of functional single crystal materials, and relates to a solid-phase reaction method for synthesizing potassium tantalum niobate solid solution polycrystalline powder by using metal oxides and a novel electro-optical functional crystal material potassium tantalum niobate melt extraction method. Pull growth method. Background technique [0002] The application of laser technology has been widely used in all aspects of industry, agriculture, military, medicine and even society, and it is playing an increasingly important role in the progress of human society. Due to its high power, convenience and flexibility, all-solid-state laser technology It has always been the top priority in the field of laser research. The generation and application of all-solid-state lasers are based on various laser crystal materials. The update and development of various crystal materials with different funct...

AI Technical Summary

Problems solved by technology

[0003] People discovered KTN crystal more than 50 years ago, and quickly discovered its superior performance in electro-optic and photorefractive aspects. KTN single crystal is very difficult. For more than half a century, people have tried various methods to grow potassium tantalum niobate crystals, but the results are not satisfactory, which makes the research and application of this crystal have been greatly restricted. The research on this crystal has been long-term has remained in the laboratory stage since

[0004] The traditional KTN crystal growth methods are molten salt method, top seed crystal method, and the improved accelerated crucible rotation method, molten salt pulling method and other growth methods. These methods have their own advantages, but they cannot To overcome two problems: First, the crystal growth process requires the use of co-solvents. For example, in the 1990s, the Institute of Crystal Materials of Shandong University used different crystal growth processes such as molten salt method and molten salt pulling method, and Designed a three-temperature zone solute transport method, successfully grown larger-sized high-quality cubic and tetragonal KTN single crystals, and studied their ferroelectric, electro-optical, and photorefractive properties

found to adopt B 2 o 3 and KF, KCl, KPO 3 , K 2 CO 3 , or K 4 P 2 o 7 Any of the mixed systems can grow KTN crystals, but there are problems such as large solvent volatilization and corrosion of quartz and refractory materials in the growth process, it is difficult to repeatedly grow large-sized crystals, and the requirements for equipment are harsh; the second is that the growth cycle is too long (one months), which increases the cost of crystal growth and limits the development and application of crystals

Therefore, these methods are only suitable for laboratory research, but not for industrial production.

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