A study of the chemical reactions involved in Li–Ca–N system

• Published in: Journal of crystal growth 2006-05, Vol.290 (2), p.621-625
• Main Authors: Yuan, W.X., Li, J., Wang, G., Cheng, A.G., Zhao, X.
• Format: Article
• Language: English
• Subjects: A1. X-ray diffraction; Applied sciences; B1. Calcium compounds; B1. Lithium compounds; B1. Nitrides; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Growth from melts; zone melting and refining; Light-emitting devices; Materials science; Methods of crystal growth; physics of crystal growth; Optoelectronic devices; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2005.12.122

The chemical reactions and phases involved in the potential flux system of Li–Ca–N for the growth of bulk GaN crystals have been investigated under varying conditions. It is found that no preferential nitrification of Li or Ca by N 2 in Li–Ca melts at 500 °C. Only the ternary compound LiCaN is identified in the Li–Ca–N system under the present experimental conditions. Static N 2 pressures are found to enhance the formation of LiCaN compared to an N 2 stream. LiCaN forms from two possible pathways: one is a modified metathesis chemical reaction represented by Li 3N+Ca→LiCaN+2Li, and the other is a combination chemical reaction represented by Li 3N+Ca 3N 2→3LiCaN. The formation of LiCaN by the metathesis reaction is thermodynamically favored over the other pathway. In addition, the formation of LiCaN might benefit from a slightly larger initial amount of Li 3N compared with Ca or Ca 3N 2.