Tm元素对SmCo_5晶体结构与磁性能的影响（英文）EI北大核心CSCD

采用X射线衍射分析(XRD)和磁性能测试等方法,分析了Tm元素掺杂对Sm Co5晶体结构和内禀磁性能的影响。XRD测试结果表明:Sm Co5和Sm0.8Tm0.2Co5.2均为Ca Cu5结构,掺杂Tm元素后,晶格常数c值增大,而a,b与晶胞体积减小;M-T曲线测试结果表明:Sm Co5和Sm0.8Tm0.2Co5.2的居里温度分别为957和965 K;在测试外加场为7 T的条件下,300 K时Sm Co5的各向异性场HA和饱和磁化强度M7T均高于Sm0.8Tm0.2Co5.2;当温度升高至473 K,Sm Co5的HA和M7T要低于Sm0.8Tm0.2Co5.2,说明Sm Co5中进行Tm元素掺杂可以有效的改善其在高温条件下的磁性能。     

共沉淀法制备GdVO4∶Tm3+蓝色荧光粉及其发光性能

采用共沉淀法制备了GdVO4∶Tm3+蓝色荧光粉,通过差热-热重(TG-DSC)分析仪,X射线粉末衍射仪、扫描电镜(SEM)及荧光分光光度计研究了前驱体晶化行为及不同制备条件对荧光粉晶体结构、颗粒形貌及发光性能的影响。研究表明：所得前驱体已有GdVO4∶Tm3+晶体形成,但结晶度较低。沉淀剂的滴定速度对荧光粉体的形貌和...     

Spectral properties of Tm,Ho:LiYF4 laser crystal

The LiYF4 single crystal codoped with thulium and holmium ions was successfully grown by the Cz method. The optimal technical parameters obtained were as follows: the pulling rate was 0.16 mm/h; the rotation speed was 3 rpm; the cooling rate was 15 °C/h. The result of XRD curve showed that as-grown Tm,Ho:LiYF4 laser crystal belonged to the monoclinic system with scheelite-type structure and space group I41/a. The cell parameters calculated were: a=0.52160 nm, c=1.09841 nm and Z=4. Absorption and fluorescence spectra of Tm,Ho:LiYF4 laser crystal at room temperature were measured and analysed. The absorption cross section, FWHM and absorption coefficient at 779.3 nm calculated were 7.44×10-21 cm2, 8.7 nm and 2.23 cm-1, respectively. An intensive fluorescence emission peak appeared near 2045 nm. The emission cross section and fluorescence lifetime were 0.87×10-20 cm2 and 10.8 ms, respectively. The ratio of Tm-Ho transfer to its back-transfer process was 10.6.     

Dy3+/Tm3+共掺GeS2-Ga2S3-PbI2玻璃的制备及其中红外发光特性研究

用熔融淬冷法制备了Dy3+/Tm3+共掺(100-x)(0.8GeS2-0.2Ga2S3)-xPbI2(mol%,x=5,10,15,20)系列玻璃样品,测试了样品热稳定性、折射率、吸收光谱、近红外及中红外荧光光谱,研究了Tm3+浓度和PbI2含量对样品中红外发光特性的影响.在Dy3+/Tm3+共掺样品中,随着PbI2...     

2μm波段Tm,Ho:YAlO_3激光器研究进展及展望

2μm波段激光在医疗、环境监测、激光雷达、遥感探测、测距领域具有十分广阔的应用,近年来成为中红外光源研究的热点。Tm,Ho:YAlO3晶体具有较好的机械和热性能,能实现多种2μm波段激光连续及脉冲输出。对国内外2μm波段Tm,Ho:YAlO3激光器的研究进展进行了归纳与总结,包括Tm/Ho单掺YAlO3激光连续及脉冲振荡技术手段,Tm,Ho:YAlO3激光连续及脉冲振荡技术手段,高功率Tm,Ho:YAlO3激光器研究的最新进展等。技术手段涉及主动调Q、被动调Q、Tm激光抽运Ho激光等,并对Tm,Ho:YAlO3激光器的进一步发展及应用给予了展望。     

Tm3+掺杂玻璃光纤研究进展

2 μm波段光纤激光可被广泛应用于激光雷达、生物医疗、环境监测以及光谱学等领域,而Tm³⁺掺杂玻璃光纤是2 μm波段光纤激光重要的增益介质。本文从Tm³⁺掺杂玻璃的发光特性出发,介绍了Tm³⁺掺杂玻璃光纤的制备技术,综述了不同玻璃基质材料掺Tm³⁺光纤的研究进展。最后,指出了制备高性能Tm³⁺掺杂玻璃光纤需要解决的关键问题,提出了可能的解决方法,并对Tm³⁺掺杂玻璃光纤发展趋势进行了展望。     

基于脉冲管制冷机的低温Tm…YAG激光器

研究了一种低温条件下(120K以下)运行的光纤耦合激光二极管(LD)端面抽运的Tm…YAG激光器。LD中心波长为785nm(15℃),光纤芯径为400μm,数值孔径为0.22。Tm…YAG晶体尺寸3mm×3mm×8mm,Tm3+掺杂原子数分数为3%。采用一种新型小型脉冲管制冷机制冷,具有冷端无振动、结构简单、寿命长的优点。将制冷机冷头与包裹晶体的紫铜热沉连接以冷却晶体,并置于真空环境中,防止结霜现象的发生。通过控制晶体温度,得到了激光器在80~290K温区内,阈值功率和输出功率随工作温度的变化关系。在晶体温度为80K,抽运功率为9W时,得到功率为3.78W的2.013μm连续激光输出,光光效率为42%,斜率效率为44.9%。     

Measurements of fast—neutron capture cross sections for ^159Tb and ^169Tm

The neutron capture cross sections for ^159Tb and ^169Tm relative to the ^197Au (n,γ)^198Au reaction are measured at neutron energies of 0.57,1.10 and 1.60 MeV by using the activation method.The activities of the products are measured with a high resolution HPGe detector gamma-ray spectrometer.The errors of the present work are 5-6% for Tb,6-7% for Tm.The recommended data in energy region of 0.4-3.0MeV are given as compared with other data published previously.     

Numerical simulation during vacuum sublimation purification of metal Tm （I）： model foundation and validation

The thermo physical parameters of Tm vapor and the range of sublimation temperature were determined by vapor pressure of metal Tm, and a 2-D axis-symmetric heat transfer model was developed to investigate the temperature distribution in sublimation furnace. The simulation results showed that, due to the heat loss at crucible bottom, the temperature of crucible, solid metal and Tm vapor increased with crucible height increasing, reached the maximum value in the middle of crucible in height direction, and then decreased rapidly; at the outside surface of condenser, the temperature decreased sharply; with heating body temperature of 1000oC, the mean temperature at upper surface of solid Tm was 22oC higher than that on the lower surface, the mean temperature of upper surface of solid Tm was about 32oC lower than that of heating body, and the calculated sublimation velocity was 8.16g/cm2/h, which was only 54.4% of sublimation velocity calculation by heating body temperature.     

Preparation and luminescence properties of BaWO4：yb3＋/Tm3＋ nano-crystal

This research investigated the effect of different contents of Tm3+and different concentration ratios of Yb/Tm on the lumi-nescent properties of BaWO4:Yb3+/Tm3+nano-crystal synthesized by the hydrother...