A Eu^3＋-doped CaCO3 phosphor with red emission was prepared by microwave synthesis. The scanning electron microscopy （SEM） image and laser particle size analysis show that the CaCO3：Eu^3＋ particles are needle-lik...A Eu^3＋-doped CaCO3 phosphor with red emission was prepared by microwave synthesis. The scanning electron microscopy （SEM） image and laser particle size analysis show that the CaCO3：Eu^3＋ particles are needle-like in the length range of 5.0-10.0 μm. The results of X-ray diffraction （XRD） analysis, Fourier transform infrared spectroscopy （FT-IR）, and Raman spectroscopy indicate that pure aragonite CaCO3：Eu^3＋ is prepared using microwave irradiation and the Eu^3＋ ion as a luminescence center inhabits the site of Ca^2＋. The photoluminescence excitation （PLE） spectrum shows that the strong broad band at around 270 nm and weak sharp lines in 300-550 nm are assigned to the charge transfer band of Eu^3＋-O^2- and intra-configurational 4f-4f transitions of Eu^3＋, respectively. The photoluminescence （PL） spectrum implies that the red luminescence can be attributed to the transitions from the ^5D0 excited level to the ^7FJ （J = 0, 1, 2, 3, 4） levels of Eu^3＋ ions with the mainly electric dipole transition ^5D0 → ^7F2 （614 and 620 nm）, and the Eu^3＋ ions prefer to occupy the low symmetric site in the crystal lattice.展开更多
基金supported by the National Natural Science Foundation of China (No. 10476024) the Science and Technology Bureau of Sichuan Province, China (No. 2006J13-059)
文摘A Eu^3＋-doped CaCO3 phosphor with red emission was prepared by microwave synthesis. The scanning electron microscopy （SEM） image and laser particle size analysis show that the CaCO3：Eu^3＋ particles are needle-like in the length range of 5.0-10.0 μm. The results of X-ray diffraction （XRD） analysis, Fourier transform infrared spectroscopy （FT-IR）, and Raman spectroscopy indicate that pure aragonite CaCO3：Eu^3＋ is prepared using microwave irradiation and the Eu^3＋ ion as a luminescence center inhabits the site of Ca^2＋. The photoluminescence excitation （PLE） spectrum shows that the strong broad band at around 270 nm and weak sharp lines in 300-550 nm are assigned to the charge transfer band of Eu^3＋-O^2- and intra-configurational 4f-4f transitions of Eu^3＋, respectively. The photoluminescence （PL） spectrum implies that the red luminescence can be attributed to the transitions from the ^5D0 excited level to the ^7FJ （J = 0, 1, 2, 3, 4） levels of Eu^3＋ ions with the mainly electric dipole transition ^5D0 → ^7F2 （614 and 620 nm）, and the Eu^3＋ ions prefer to occupy the low symmetric site in the crystal lattice.
