Purification Of Impurities Research Articles

Al Impurity Purification in Quartz Grown by the Hydrothermal Method

Al impurity purification in synthetic quartz grown by the hydrothermal method was studied by atomic absorption spectroscopy. The purification process can be expressed by the equation. Alsq=a· exp (b·Allasca), with Alsq and Allasca representing the respective Al contents in synthetic quartz and lascas used as the nutrient. a and b are constants which depend on the growth condition. Analytical data showed different Al content depending on growth region: it was highest in the S-region and lowest in the Z-region. Al content in the Z-region did not significantly differ (∼10 ppm), when the nutrient used for crystal growth had an Al content of between 29 ppm and 240 ppm. S-regions were not purified when the nutrient with Al content of less than 30 ppm was used. Influence of Al content on crystal morphology in the purification process was discussed.