Millimeter-sized sodalite single crystals grown under high-temperature, high-pressure hydrothermal conditions

✍ Scribed by Tsuyoshi Shiraki; Toru Wakihara; Masayoshi Sadakata; Masahiro Yoshimura; Tatsuya Okubo

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 369 KB
• Volume: 42
• Category: Article
• ISSN: 1387-1811
• DOI: 10.1016/s1387-1811(00)00322-x

✦ Synopsis

Millimeter-sized sodalite single crystals are grown under high-temperature, high-pressure hydrothermal conditions. A gold-lined autoclave is used to remove the contaminants from the reactor wall. Spontaneous nucleation mode is studied at ®rst. As the synthesis time was extended, sodalite crystals grow from spontaneous nucleation; however, the formation of a by-product of nepheline hinders the further growth of sodalite after 10 h. Optimizing the synthesis time, a 0.25 mm sodalite crystal is obtained. Based on this result, the seeded growth is studied, and the single crystals larger than 1.0 mm are reproduced without the by-product formation. The maximum sodalite single crystal was 2.6 mm in diameter. Throughout the seeded growth, it is found that the control of the temperature pro®le at the cooling-down stage is a key to enlarge the crystal size. The product is a sodalite single crystal with high quality.