Results of TDLS application for ammonia monitoring in a process of high-purity arsine and phosphine production

• Published in: Applied physics. B, Lasers and optics Lasers and optics, 2010-08, Vol.100 (2), p.391-396
• Main Authors: Kotkov, A. P., Ivanov, V. A., Grishnova, N. D., Shirayev, A. V., Berezin, A. G., Nadezhdinskii, A. I., Ponurovskii, Y. Y., Popov, I. P., Shapovalov, Y. P., Stavrovskii, D. B., Vyazov, I. E.
• Format: Article
• Language: English
• Subjects: Ammonia; Engineering; Impurities; Lasers; Magnesium; Monitoring; Monitors; Optical Devices; Optics; Phosphines; Photonics; Physical Chemistry; Physics; Physics and Astronomy; Purification; Quantum Optics
• ISSN: 0946-2171; 1432-0649
• DOI: 10.1007/s00340-009-3895-z

Using the TDLS method it has been found that ammonia (NH 3 ) is the main impurity in arsine (AsH 3 ) and phosphine (PH 3 ), produced by hydrolysis of magnesium arsinide and phosphinide, respectively. NH 3 behavior is abnormal in solutions of these hydrides: NH 3 reveals the properties of a more volatile impurity in relation to arsine and phosphine, although its boiling temperature is higher than that of AsH 3 and PH 3 . The observable anomaly is connected with the fact that in solutions of arsine and phosphine NH 3 shows properties differing from the properties of pure ammonia. It was supposed that the influence of intermolecular interaction between ammonia molecules, when diluted by arsine or phosphine, decreases. During the purification of arsine or phosphine one must continuously monitor the NH 3. concentration in the extraction of the light fraction in order to define the point at which to terminate the purification process.