The hexagonal born nitride based yellow afterglow phosphor was prepared by the rapid combustion method and its luminescent properties were characterized. The phosphor prepared at 800 ℃ for 30 min is with excellent luminescent performance. After irradiation by UV light, the yellow long-lasting phosphorescence can be observed for above 2 h in the limit of light perception of dark-adapted human eyes(0.32 mcd·m-2).
LaF3 nanowires with high aspect ratios have been prepared via a low-temperature solvothermal method using LaCl3 and KF or NH4F as starting materials in absolute alcohol at 160 ℃ for 12 h. XRD pattern and TEM images show that the products are hexagonal structure with diameter of 80 nm and length up to 8 μm. The lanthanum sources played most important roles, reaction temperature and time also played important roles in the morphology control of final LaF3 products. The optimal conditions for ideal LaF3 nanowire are at a reaction temperature of 160 ℃ and reaction time for 14 h using LaCl3 and NH4F as starting materials. A possible formation mechanism for LaF3 nanowires is proposed.
