稀土镨掺杂的CaTiO3，La2O3发光材料的制备与表征

稀土镨掺杂的CaTiO3，La2O3发光材料的制备与表征
　　In this paper, adopted CaTiO3 and La2O3 as the hosts, two kinds of Pr3+-doped phosphors were prepared used different starting materials and by different methods, and characterized by PL spectrum, UV-Vis spectrum, XRD, SEM, FT-IR spectrum, DTS-TG The PL property and mechanism of Pr3+ doped in the two hosts were discussed respectively. The influence to the PL intensity and morphology of experimental conditions and synthetical methods were also studied.According to PL and UV-Vis spectrum, the process of luminescence of CaTiO3:Pr3+ can be described as the host absorbed the UV light, and transferred the energy to Pr3+. It can be excitated to neodymium magnets 5d states when Pr3+ gained the energy, and came back to 1D2 spectrum level by nonradiative transition on the instant, then transferred from 1D2 to 3H4, and ultimately, the red light with the wavelength of 613nm was emitted. Pr3+ also can be excitated to 5d states after absorbed the UV light by itself in La2O3:Pr3+. But it came back to 3P0 spectrum level by nonradiative transition, then transferred from 3P0 to 3H4, and emitted green light with the wavelength of 510 nm.
　　The energy level of charge transfer state(CTS) of Pr3+ is lower enough that 3P0 can not exist stably but easy to transfer to 1D2 by CTS in CaTiO3:Pr3+, and only can emit red light. This is also the main reason to explain the difference of luminescence of Pr3+ in the two hosts.When studied the influence to PL intensity of experimental conditions in the process of synthesizing CaTiO3:Pr3+, we found the traditional solid state reaction is better than liquid state reaction(sol-gel method, precipitation method), and prefer TiO2 aerogel to common TiO2 as the starting material. Improving sintering temperature conduce to intensifying the visible emission, and when sintered at 1200℃, CaTiO3:Pr3+ appears the most intense emission. The quench concentration of Pr3+ in CaTiO3:Pr3+ http://www.chinamagnets.biz/ is only 0.1% due to the exist of cross relaxation.The PL intensity of CaTiO3:Pr3+ can be enhanced at 325 nm when Al3+ was doped. It is attribute to charge compensation by Al3+ co-dope and eliminating more charge defects which produced by Pr3+ substituting Ca2+. The optimal concentration of Al3+ doped is between 8% and 15%. In this concentration range, the PL intensity become most intense, but this result is consistent with theoretical value of charge compensation. This result is also proved the