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The effects of Er3+ ion concentration on 2.0-μm emission performance in Ho3+/Tm3+ co-doped Na5Y9F32 single crystal under 800-nm excitation 下载免费PDF全文
Na5Y9F32 single crystals doped with ~0.8-mol% Ho3+,~1-mol% Tm3+,and various Er3+ ion concentrations were prepared by a modified Bridgman method.The effects of Er3+ion concentration on 2.0-μm emission excited by an800-nm laser diode were investigated with the help of their spectroscopic properties.The intensity of 2.0-μm emission reached to maximum when the Er3+ ion concentration was ~1 mol%.The energy transfer mechanisms between Er3+,Ho3+,and Tm3+ ions were identified from the change of the absorption spectra,the emission spectra,and the measured decay curves.The maximum 2.0-μm emission cross section of the Er3+/Ho3+/Tm3+tri-doped Na5Y9F32 single crystal reached 5.26 × 10-21 cm2.The gain cross section spectra were calculated according to the absorption and emission cross section spectra.The cross section for ~2.0-μm emission became a positive gain once the inversion level of population was reached 30%.The energy transfer efficiency was further increased by 11.81% through the incorporation of Er3+ ion into Ho3+/Tm3+ system estimated from the measured lifetimes of Ho3+/Tm3+-and Er3+/Ho3+/Tm3+-doped Na5Y9F32single crystals.The present results illustrated that the Er3+/Ho3+/Tm3+tri-doped Na5Y9F32 single crystals can be used as promising candidate for 2.0-μm laser. 相似文献
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在DMSO/I2的氧化作用下,由2′,4′-二氢-6′-甲氧基-3′,5′-二甲基查耳酮可合成一种全新结构的黄酮:7-羟基-5-甲氧基-6,8-二甲基黄酮(产率91%),而在HCl/MeOH作用下则得到了两种黄烷酮:7-羟基-5-甲氧基-6,8-二甲基黄烷酮(产率70%)和5,7-二羟基-6,8-二甲基黄烷酮(产率20%)。 相似文献
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以5-甲基色胺盐酸盐和邻溴苯乙酸为例, 研究了5-甲基色胺衍生物的合成方法. 在室温下用二环己基碳二亚胺(DCC)作为脱水剂, N-羟基琥珀酰亚胺(NHS)活化酯法一锅法合成5-甲基色胺衍生物, 并通过FTIR、MS、1H NMR、13C NMR确定了目标化合物结构. 相似文献
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设计合成了一种有机膦离子液体[Ph3PC4P(O)Ph2]PF6(IL-2)及其稀土铕配合物Eu(IL-2)3(NO3)3,并通过核磁、高分辨质谱、元素分析确认了它们的结构。热重分析表明IL-2和Eu(IL-2)3(NO3)3具有很好的热稳定性。从红外光谱中可以看出,形成配合物后,P=O的吸收峰向低波数方向移动;配合物Eu(IL-2)3(NO3)3的紫外吸收强度大于游离的IL-2,说明Eu3+和IL-2中的磷酰基发生了配位。在核磁共振磷谱中,配合物的P=O的化学位移发生了显著变化,从游离配体的32 ppm变化到-110 ppm,而季磷原子和PF6-的化学位移没有变化,也表明P=O基团直接与稀土配位。Eu(IL-2)3(NO3)3荧光光谱表现出Eu3+的特征红光,峰形尖锐,单色性好,表明该配合物是一种潜在的红色发光材料。 相似文献
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