Showing 3 results for M. J. Tafreshi
M. J. Tafreshi1, M. Fazli2,
Volume 6, Issue 2 (Spring 2009 2009)
Abstract
Abstract:
fabricated. Modifications carried out in different parts of the old system in order to control most
of the growth parameters with more accuracy. The fabricated system was used to grow sapphire
single crystals with almost 10 mm in diameter and 50 mm in length. The crystallinity and
structure of the grown crystals were characterized by computer aided single crystal X-ray
diffraction technique.
A Verneuil system, more sophisticated than a conventional one, has been designed and
M. J. Tafreshi, B. Dibaie, M. Fazli, M. Alidaie,
Volume 8, Issue 1 (winter 2011 2011)
Abstract
M. J. Tafreshi, B. Dibaie, M. Fazli,
Volume 9, Issue 1 (march 2012 2012)
Abstract
Abstract: A thermodynamic model was used to find out the optimum temperature for the growth of ZnS single crystals in closed ampoules by chemical vapor transport technique. Based on this model 1002 °C was found to be optimum temperature for 2 mg/cm3 concentration of transporting agent (iodine). ZnS Crystals were grown in optimum (1002 °C) and non-optimum (902 °C and 1102 °C) temperatures. The composition structure and microstructure of the grown crystals were studied by Atomic absorption spectroscopy, X-ray diffraction and Scanning electron microscopy measurements. Properties of the grown crystals were correlated to the growth conditions especially a stability in mass transport along the closed tube length.