Abstract
Morphological control of Sn2+ doped calcium carbonate phosphors by crystallizing amorphous calcium carbonate formed from aqueous solution reaction of CaCl2-(NH4)2CO3-SnCl2 system and its fluorescence property were investigated. Amorphous calcium carbonate changed into spherical and platelike vaterites at 15-50°C and needlelike aragonite above 60°C. In order to obtain calcite, a suspension of vaterite formed at 20°C by crystallizing amorphous calcium carbonate was kept at 90°C for 120min. The content of Sn2+ in platelike vaterite crystal was Sn/CaCO3 mol% of approximately 0.4 and was about 4 times as compared with that of rhombohedral calcite crystal. The emission spectrum of rhombohedral calcite phosphors with Sn2+ of 0.04mol% showed bright blue fluorescence at 465nm. Its optimum excitation wavelength was wavelength of ultraviolet irradiation at 255nm.
