| Autor: | Changkang Chen, R. C. C. Ward, B. E Watts, B.M. Wanklyn |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Steady state
Diffusion equation Materials science Diffusion Thermodynamics Crystal growth Condensed Matter Physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention law Growth rate Electrical and Electronic Engineering Crystallization Supercooling Dissolution |
| Zdroj: | Journal of Materials Science Materials in Electronics. 9:255-260 |
| ISSN: | 0957-4522 |
| Popis: | The crystallization temperatures of KTiOPO4(KTP), KTP : Nb and RbTiOPO4(RTP) in the flux systems, K6P4O13 (K6) or Rb6P4O13 (R6), were determined by thermogravimetric analysis. The systems have a large tendency to supercool, which could be greatly reduced by the top-seeding technique. Seed-testing experiments were used to study the dissolution kinetics. The diffusion equation under steady state conditions was used to derive an expression for the seed dissolution, which enables one to introduce the diffusion activation energy and the diffusion rate parameter from the experimental data. Consequently, the stable growth rate and the cooling programme for the crystal growth can be estimated. The stable growth rate decreases with temperature and is in the order of 0.1 mm day-1 in unstirred solutions. The optimal cooling rate curve, however, goes through a maximum as the temperature falls. A stable growth rate and suitable supercooling are essential for the growth of large single crystals of high quality. © 1998 Chapman & Hall |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink