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利用高温固相反应法合成了Ce4 和Eu3 共掺杂的Ca2-xEuxSn1-yCeyO4样品,并对其结构和发光特性进行了研究。X射线衍射结果显示,在Ca2SnO4中同时掺入Ce4 和Eu3 离子没有改变其晶体结构。Ca2-xEuxSn1-yCeyO4样品的发射光谱随Eu3 掺杂浓度产生很大变化,当Eu3 掺杂浓度低时,样品中同时存在着Ce4 -O2-的蓝光发射和Eu3 的红光发射;当Eu3 掺杂浓度较高时,样品呈现出Eu3 离子的红光发射。Ce4 -O2-蓝色发光的寿命约为81μs,其能量来源于O2-和Ce4 离子间的电荷迁移吸收;而Eu3 红色发光的寿命约为830μs,其能量来源于O2-和Eu3 离子间的电荷迁移吸收。Eu3 -O2-键比Ce4 -O2-键更容易吸收紫外光,两者之间没有能量传递现象。 相似文献
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Synthesis and characterization of Ca2Sn1-xCexO4 with blue luminescence originating from Ce^4+ charge transfer transition 下载免费PDF全文
Ce^4+-doped Ca2SnO4 with a one-dimensional structure, which emits bright blue light, is prepared by using a solid-state reaction method. The x-ray diffraction results show that the Ce^4+ ions doped in Ca2SnO4 occupy the Sn^4+ sites. The excitation and emission spectra of Ca2Sn1-xCexO4 appear to have broad bands with peaks at - 268nm and -442nm, respectively. A long excited-state lifetime (-83μs) for the emission from Ca2Sn1-xCexO4 suggests that the luminescence originates from a ligand-to-metal Ce^4+ charge transfer (CT). The luminescent properties of Ca2Snl_xCexO4 have been compared with those of Sr2CeO4, which is the only material reported so far to show Ce^4+ CT luminescence. More interestingly, it is observed that the emission intensity of Ca2Sn1-xCexO4 with a small doping concentration (x - 0.03) is comparable to that of Sr2CeO4 in which the concentration of active centre is 100%. 相似文献
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A Eu3+-doped Ca2PbO4 with one-dimensional structure was prepared with a solid-state reaction method and its characteristics were investigated. The XRD results show that the substitution of Ca2+ by Eu3+ has no influence on the structure of Ca2PbO4. Under the excitation of ultraviolet light, the Ca2PbO4:Eu3+ phosphor exhibits strong red emission at about 618 nm which is assigned to the 5D0- 7F2 electric-dipole transition. The compounds Sr2CeO4 and Ca2SnO4 have the same crystal symmetry as that of Ca2PbO4 and it is found that the emission intensity of Ca2PbO4∶Eu3+ is higher than that of Sr2CeO4∶Eu3+ and lower than that of Ca2SnO4∶Eu3+. The excitation spectrum of Ca2PbO4∶Eu3+ appears to be a broad band with two peaks at about 289 nm and 340 nm. The former peak is attributed to the Eu3+-O2- charge transfer transition, while the latter one may be related to the absorption of Ca2PbO4 host or its crystal defects. 相似文献
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