Precipitation of bismuth and bismuth sulfide in borate glasses

摘要

Fine particles of Bi and Bi_2S_3 formed by precipitation from Na_2O-B_2O_3 glasses have been studied. Bi metal particles were formed by reduction of Bi_2O_3 by SnO added to the glass matrices. The size of particles was controlled by the heat-treatment time of the sample glasses. The shape and size of these precipitates were observed by the transmission electron microscope (TEM) and the microscopic structure was studied by XAFS. The melting temperature of these particles has been discussed in terms of thermodynamics. Bi_2S_3 was dissolved in the melts and then precipitated as fine particles from the quenched glasses. A preliminary experiment on the growth of Bi_2S_3 has been made using TEM and XAFS.