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采用高温固相法在1 350 ℃弱还原气氛下制备了Sr1-xBaxAl2O4 : Eu2+ ,Dy3+ (x=0,0.2,0.4,0.6,0.8,1.0)长余辉材料,并对其微观结构和发光特性进行了分析。X射线衍射结果表明,当钡的掺杂摩尔分数x<0.4时,样品晶体结构为SrAl2O4单斜晶系结构;当x≥0.4时,样品晶体结构为BaAl2O4六角晶系结构;而且随着钡对锶的取代,两种晶体结构的晶格常数都发生了一定程度的膨胀。光致发光测试结果表明,当x从0增大到1.0时,样品发射波长峰值也相应由515 nm逐渐蓝移到494 nm。通过热释光谱测试表明, SrAl2O4结构的样品的热释光峰所对应的温度比BaAl2O4 结构的要高,且对应SrAl2O4结构的样品的余辉时间更长,初始亮度更高。 相似文献
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本文介绍了单光子计数技术的基本原理,并通过对长余辉发光材料余辉衰减的测量,说明了单光子计数在精确测量弱光衰减过程中的优点。 相似文献
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研究了真空热处理对多壁碳纳米管(MWNTs)电化学储氢性能的影响.采用化学气相沉积法(CVD)制备碳纳米管,碳纳米管与LaNi5储氢合金按质量比1∶10混合,制作成CNTs-LaNi5电极.电解池采用三电极体系,6mol/L KOH为电解液,Ni(OH)2为正极,Hg/HgO为参比电极.实验结果表明,在相同的充放电条件下,850℃时CNTs-LaNi5电极的储氢性能最好,克容量最大为503.6mAh/g,相应的平台电压高达1.18V.从500—850℃随着温度升高,放电量有较大幅度的增加,但到950℃时放电量反而下降.由此可见,碳纳米管的热处理温度对碳纳米管的电化学储氢性能有着较大的影响.
关键词:
碳纳米管(CNTs)
储氢性能
5合金')" href="#">LaNi5合金
化学气相沉积法(CVD法) 相似文献
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Effect of H_3BO_3 on the phase stability and long persistence properties of Sr_(3.96)Al_(14)O_(25):Eu_(0.01)~(2+), Dy_(0.02)~(3+) phosphor
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Sr3.96Al14O25:Eu2+ ,Dy3+ long persistent materials with different weights of H3BO3 prepared by the high temperature solid-state reaction method were characterized by X-ray powder diffraction (XRD), scanning electronic microscopy (SEM), photoluminescence spectra (PL), and thermoluminescence (TL). The results of XRD indicate that the 3% addition of H3BO3 favorable for the formation of pure phase Sr4Al14O25 , and SrAl12O19 was generated when there is a low content or high content of H3BO3 . The average grain sizes of samples grow bigger with an increase of H3BO3 . PL spectra show that the emission peak does not shift evidently and the emission intensity changes little, indicating that the different amount of H3BO3 has little influence on the crystal field. The decay characteristics and TL measurement show that H3BO3 affects the afterglow properties of Sr3.96Al14O25 :Eu2+ ,Dy3+ , because the increasing H3BO3 leads to more defects in the Sr4Al14O25 matrix. 相似文献