By the DC arc-discharge of graphite rods doped with other substances in He and NH3 mixing gas,higher endohedral metallofullerenes(EMFs) were synthesized in a high yield. This lays the foundation for the separation,pur...
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By the DC arc-discharge of graphite rods doped with other substances in He and NH3 mixing gas,higher endohedral metallofullerenes(EMFs) were synthesized in a high yield. This lays the foundation for the separation,purification and further study of higher EMFs. The doped materials act as heat carriers and at the same time catalyze the growth of higher EMFs,whereas NH3 suppresses the formation of fullerenes such as C60 and C70,etc.
Tb3+ ions were incorporated in P Si matrix material through a sol gel process. Luminescence properties of Tb3+as a function of dopant, firing temperature, composition and structure of matrices were investigated. The g...
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Tb3+ ions were incorporated in P Si matrix material through a sol gel process. Luminescence properties of Tb3+as a function of dopant, firing temperature, composition and structure of matrices were investigated. The gels synthesized by the reaction of P2O5 or H3PO4 with tetraethoxy silane and TbCl3 as dopant were fired in air from the temperature 25～1000℃to form P Si crystalline phase. The crystal structure was determined by powder X ray diffraction. Si5O（PO4）6 were the only crystalline phase and belong to hexagonal crystal system. The emission of 5D4 7F5（～545nm） transition of Tb3+in the P Si system iscomposed of two peaks. The amount of doping Tb3+varied from 0.664%to 1.644%, and no obvious concentration quenching was observed in this doping concentration range. The intensity of Tb3+emission increased with firing temperatureincreasing and becomes stable at 800～1000℃.
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