共查询到19条相似文献,搜索用时 156 毫秒
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Sol-gel法制备Er3+-Yb3+共掺杂Al2O3粉末光致发光特性 总被引:8,自引:7,他引:1
采用异丙醇铝[Al(OC3H7)3]为前驱体,溶胶-凝胶(Sol-gel)法制备Er3+-Yb3+共掺杂Al2O3粉末.实验结果表明:900 ℃烧结的粉末为固溶Er3+、Yb3+的γ-(Al,Er,Yb)2O3相和少量θ-(Al,Er,Yb)2O3相的混合物.Er3+-Yb3+共掺杂Al2O3粉末具有中心波长为1.533 μm的光致发光(PL)特性.1 mol % Er3+和1 mol% Yb3+共掺杂的Al2O3粉末的PL强度较1 mol % Er3+掺杂提高2倍,半峰宽从53 nm增加到63 nm.随泵浦功率的提高,PL强度呈线性增加后渐呈饱和趋势. 相似文献
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研究了R2O—B2O3—SiO2系统玻璃中的双碱(KO2、Na2O)效应,引入Al2O3的抗水效应,硼酸盐的挥发,加入CaF2等澄清剂对玻璃粘度,透光率等影响,并在此基础上确定了在R2O—B2O3—SiO2系统玻璃中能与光导纤维芯玻璃F626/356匹配良好的包层玻璃的基础成份:SiO269~71,B2O38~12,R2O11~20(均为Mol%),在基础成分中添加少量的Al2O3、RO(CaO、MgO、ZnO)及适量的CaF2等澄清剂、制得了具有不同温度变化的粘度,折射率(ND-1.1537~1.5163)和热膨胀系数值室温15°~120℃范围,α=(79.1~81.0)×10-7/℃的包层玻璃。其中BP—81—16号包层玻璃已投入生产,它与光纤芯玻璃F626/356组合拉制的光导纤维的性能远优于改良3号**光导包层玻璃。 相似文献
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对CuO-Al粉末预制块经不同温度下反应,测试其温度随时间的变化曲线,利用X射线衍射仪对其反应后的试样进行物相分析,得出产生热爆的反应温度及不同温度下的反应产物。 结果表明,CuO-Al体系反应随介质温度升高,可分为3个不同阶段,温度小于1 200 K,不发生化学反应;温度为1 200~1 473 K时CuO-Al体系发生部分化学反应,其产物为Cu2O、CuAlO2 及Al2O3;温度高于1 473 K,CuO-Al体系发生化学反应,其产物为Cu和Al2O3,此阶段易出现热爆现象。 相似文献
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采用金刚石压砧高压装置,研究了双钙态矿结构化合物Sr2FeNbO6及其掺杂物Sr2FeMo0.3Nb0.7O6在室温下,20 GPa内电阻和电容随压力的变化,并发现Sr2FeNbO6在7.5 GPa左右压力下发生了相变,而Sr2FeMo0.3Nb0.7O6的相变发生在2.8 GPa左右。并结合这两个样品的高压下的同步辐射能散X射线衍射实验,进一步证明了这两种相变是电子结构相变引起的。 相似文献
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本文首次研究了Al80Mn14Si6合金在静高压下准晶相得形成。利用静高压熔态淬火方法,在压力2.8和3.1 GPa下得到淬火的Al-Mn-Si样品。电子和X射线衍射实验表明,高压淬火样品中含有准晶二十面体相和非晶相。X射线衍射实验还表明,高压淬火样品经350 ℃退火一小时基本上没有发生变化;而经过500 ℃退火一小时后,准晶相晶化为α-Al73Si10Mn17相。另外,电子衍射实验表明,高压淬火后样品中还存在其它中间亚稳相。本文还讨论了静高压熔态淬火方法的适用性。 相似文献
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高温高压条件下对钙钛矿(Perovstsite)多晶进行了研究,在金刚石压砧设备上压力条件最高达38 GPa,YAG莱塞加热温度近1 000 ℃以上,用红宝石荧光校压系统进行压力标定。实验结果表明静水压条件X射线就位测量,GaTiO3(Ⅰ)由斜方晶系在10 GPa时直接向六方GaTiO3(Ⅱ)结构相变,体积变化为1.6%;1 000 ℃加热及其非静水压条件下GaTiO3(Ⅰ)由斜方晶系首先转变为四方晶系GaTiO3(Ⅲ)转变压力为8.5 GPa,体积变化为0%,继续增加压力导15 GPa,GaTiO3(Ⅲ)向GaTiO3(Ⅱ')转化成六方晶系,体积变化亦为1.6%。三种高压相,在压力降到一个大气压时都会消失,所以是逆转化的非淬火相。等温压缩在标准静水压条件下进行,压力应小于10.4 GPa,K0'=5.6时,K0=(210±7)GPa,此数据是根据Birch-Murnaghan状态方程求得的体模量。 相似文献
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Based on a new approach for designing glassy alloy compositions, bulk Al-based alloys with good glass-forming ability (GFA) are synthesized. The cast Al86Si0.5Ni4.06Co2.94 Y6Sc0.5 rod with a diameter of i mm shows almost fully amorphous structure besides about 5% fcc-Al nucleated in the center of the rod. The bulk alloy with high Al concentration exhibits an ultrahigh yield strength of 1.18 GPa and maximum strength of 1.27 GPa as well as an obvious plastic strain of about 2.4% during compressive deformation. This light Al-based alloy with good GFA and mechanical properties is promising as a new high specific strength material with good deformability. 相似文献
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K. Kołodziejak S. Turczyński R. Diduszko L. Klimek D. A. Pawlak 《Opto-Electronics Review》2006,14(3):205-211
Eutectics are the materials with foreseen application in the field of photonic crystals and metamaterials. In this paper,
the dependence on chemical composition of the microstructures of terbium-scandium-aluminium gamet and terbium-scandium perovskite
(Tb3Sc2Al3O12-TbScO3) eutectics has been studied. The growth of the eutectic rods by the micro-pulling down method is presented, using compositions
with several different volume fractions of the garnet and the perovskite phases, VTSAG:VTSP = 4, 3, 2, 1, 1/2. The phases have been characterized by powder X-ray diffraction and energy dispersive spectrometry. The
relationship between the lattice constant of individual phases and the chemical composition is presented. The unidirectional
growth of microrods has been also investigated by electron backscattering diffraction. 相似文献
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利用辐射法测量金属材料的冲击波温度时,在金属样品/透明窗口界面上卸载引起的熔化对卸载终态的影响进行了探讨,提出了利用“过热”卸载模型计算由于卸载熔化对终态的影响及计算公式,并给出了几种典型压力下Fe/Al2O3及Fe/LiF界面在考虑卸载熔化后的温度、熔化质量分数及体积。 相似文献
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Epitaxial Properties of Co-Doped ZnO Thin Films Grown by Plasma Assisted Molecular Beam Epitaxy 总被引:1,自引:0,他引:1
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High quality Co-doped ZnO thin films are grown on single crystalline Al2O3(0001) and ZnO(0001) substrates by oxygen plasma assisted molecular beam epitaxy at a relatively lower substrate temperature of 450℃. The epitaxial conditions are examined with in-situ reflection high energy electron diffraction (RHEED) and ex-situ high resolution x-ray diffraction (HRXRD). The epitaxial thin films are single crystal at film thickness smaller than 500nm and nominal concentration of Co dopant up to 20%. It is indicated that the Co cation is incorporated into the ZnO matrix as Co^2+ substituting Zn^2+ ions. Atomic force microscopy shows smooth surfaces with rms roughness of 1.9 nm. Room-temperature magnetization measurements reveal that the Co-doped ZnO thin films are ferromagnetic with Curie temperatures Tc above room temperature. 相似文献