共查询到20条相似文献,搜索用时 125 毫秒
1.
用硝酸盐热分解法成功制备了BaZr(BO3)2:Eu(Eu3+的掺杂量为摩尔分数5%)荧光材料,并研究了其在254及147 nm光束激发下的发光特性.254 nm光束激发下的发射主峰位于612 nm处,归属于Eu3+的5D0-7F2的电偶极跃迁,但在147 nm光束激发下的发射主峰位于592 nm处,归属于Eu3+的5D0-7F1的磁偶极跃迁.通过激发光谱分析,上述现象归因于在紫外激发下占据非对称格位Ba2+的Eu3+被优先激发,而在真空紫外激发下占据对称格位Zr4+的Eu3+被优先激发.结果表明BaZr(BO3)2:Eu并不适合作为等离子平板显示器用红色发光材料. 相似文献
2.
3.
4.
5.
6.
首先测量了ZBLAN∶Yb3 ,Tm3 分别在980nm和808nm激光激发下的400~600nm波段内的上转换发光光谱,在此基础上研究了980,808nm激光共激发下ZBLAN∶Yb3 ,Tm3 的上转换发光特性。在测量过程中,分别改变输入激光功率,测量了上转换发光强度与泵浦激光输入功率的关系,由此绘制双对数曲线图,对上转换发光机制进行了分析。研究证明980nm激发为三光子过程、808nm激发为双光子过程,而980,808nm激光共同激发为共协过程。 相似文献
7.
用高温固相法制备了Sr_7Zr(PO_4)_6∶Tb~(3+)、Sr_7Zr(PO_4)_6∶Ce~(3+)及Sr_7Zr(PO_4)_6∶Tb~(3+),Ce~(3+)一系列荧光粉,并通过X射线衍射仪及荧光光谱仪分析了其结构和发光性质。结果表明,Sr_7Zr(PO_4)_6∶Tb~(3+)呈现特征绿色发射,最强发射峰位于543 nm,属于Tb~(3+)的5D4→7F5跃迁,激发峰位于226 nm处,但激发带较窄。为拓宽其激发带的宽度,在Sr_7Zr(PO_4)_6∶Tb~(3+)中掺入了Ce~(3+),观察到掺入Ce~(3+)后激发带变宽,且在Ce~(3+)的激发波长处激发得到了Tb~(3+)的发射,表明存在Ce~(3+)到Tb~(3+)的能量传递。 相似文献
8.
用方波电源驱动808 nm,980 nm激光二极管(LD)激发Er3+掺杂的亚碲酸盐氟氧化物玻璃,测量2H11/2,4S3/2能级上转换发光的上升和衰减,不同波长激发下的上升时间常数不同,说明808 nm LD和980 nm LD激发下2H11/2,4S3/2能级上转换激发途径不同.通过建立速率方程模型分析了4S3/2能级的上升特性与中间能级寿命的关系,从而确定了两种波长激发下上转换绿光的激发机理.
关键词:
上转换
激发过程
3+')" href="#">Er3+
方波激发 相似文献
9.
本文通过Er~(3 )离子激发过程的效率和最终发射过程的效率测定了Yb~(3 )—Er~(3 )激活的上转换磷光体的效率。激发过程依赖于红外激发强度。我们用不同的基质晶格,激发到选定的Er~(3 )能级,测量了发射过程的效率,而且作为Yb~(3 )和Er~(3 )浓度的函数。现在知道的最好的上转换磷光体之一,α-NaYF_4—0.20Yb—0.03Er的绿色发光效率约为6%。 相似文献
10.
采用高温固相法合成了不同Yb3+和Er3+掺杂浓度的BaIn6Y2O13上转换发光材料。XRD数据显示,所合成的BaIn6Y2O13∶Yb3+, Er3+属于六方晶系,引入激活剂并没有改变基质的晶体结构。利用971 nm半导体激光器激发样品,测量样品在不同激发光密度下上转换发射光谱和发射光功率,计算了上转换能量效率。数据表明在激发密度不变,激活剂浓度增加时,上转换光绿红比减小;激活剂浓度不变激发光密度增加时,发射光绿红比增大。分析表明是由于Er3+之间的交叉弛豫增强导致绿红比随激活剂掺杂浓度的增加而减小;Yb3+和Er3+之间的能量传递和Er3+的激发态吸收增强导致绿红比随激发密度的增加而增大。随着激发功率增加, 在较低激发功率时, 上转换绿光发射强度与激发功率的二次方成正比; 在较高激发功率时, 上转换绿光发射强度与激发功率的一次方成正比, 与报道的结果一致。能量效率存在极大值, 分别为0.38%(Yb3+掺杂浓度3%, Er3+掺杂浓度1%)和0.06%(Yb3+掺杂浓度9%, Er3+掺杂浓度3%), 产生极值的一个原因是4I13/2亚稳态能级寿命较长, 聚集了大量电子, 使基态电子急剧减少, 导致上转换泵浦效率降低。 相似文献
11.
采用FT-拉曼光谱技术,测定正氢和仲氢的转动拉曼光谱,计算出正氢和仲氢分子的核间距分别是75.03和74.98pm(1pm=10^-12m)。 相似文献
12.
We study Heisenberg antiferromagnets with nearest- (J1) and third- (J3) neighbor exchange on the square lattice. In the limit of spin S-->infinity, there is a zero temperature (T) Lifshitz point at J(3)=1/4J(1), with long-range spiral spin order at T=0 for J3>1/4J(1). We present classical Monte Carlo simulations and a theory for T>0 crossovers near the Lifshitz point: spin rotation symmetry is restored at any T>0, but there is a broken lattice reflection symmetry for 0< or =T相似文献
13.
低泵浦能量类氖锗等离子体软X射线激光实验 总被引:2,自引:1,他引:1
提出并采用具有一定时间间隔的双束脉冲加热锗薄膜靶方法,在泵浦激光能量100J,靶长10mm的实验条件下,观察到波长19.61nm和23.63nm两条类氖锗3s-3p激光跃迁线。19.61nm(J=0-1)的激光跃迁线发射强度较23.63nm(J=2-1)激光线的强度大,其发散角较后者小。 相似文献
14.
Bound states made from two triplet excitations on the Shastry-Sutherland lattice are investigated. Based on the perturbative unitary transformation by flow equations quantitative properties like dispersions and qualitative properties like symmetries are determined. The high order results [up to (J2/J1)(14)] permit one to fix the parameters of SrCu2(BO3)(2) precisely: J1 = 6.16(10) meV, x J2/J1 = 0.603(3), J( perpendicular) = 1.3(2) meV. At the border of the magnetic Brillouin zone a general double degeneracy is derived. An unexpected instability in the triplet channel at x = 0.63 indicates a transition towards another phase. The possible nature of this phase is discussed. 相似文献
15.
在对GeⅣ—RuⅩⅥ离子3d-94s4p组态能级结构的组态相互作用理论分析计算的基础上,进一步分析了关联效应,量子电动力学(QED)效应及其他效应对等电子序列离子能级结构的影响,找出了沿等电子序列离子能级变化的规律性.在前人研究工作的基础上,预测计算了MoⅩⅣ—RuⅩⅥ离子3d-94s4pJ=12,32组态能级,由此计算了MoⅩⅣ—RuⅩⅥ离子3d-104s—3d-94s4pJ=12,32跃迁谱线波长,振子强度和跃迁概率.
关键词:
GeⅣ—RuⅩⅥ离子
谱线波长
振子强度
跃迁概率 相似文献
16.
Rule KC Wolter AU Süllow S Tennant DA Brühl A Köhler S Wolf B Lang M Schreuer J 《Physical review letters》2008,100(11):117202
We present a specific heat and inelastic neutron scattering study in magnetic fields up into the 1/3 magnetization plateau phase of the diamond chain compound azurite Cu3(CO3)2(OH)2. We establish that the magnetization plateau is a dimer-monomer state, i.e., consisting of a chain of S=1/2 monomers, which are separated by S=0 dimers on the diamond chain backbone. The effective spin couplings Jmono/kB=10.1(2) K and Jdimer/kB=1.8(1) K are derived from the monomer and dimer dispersions. They are associated to microscopic couplings J1/kB=1(2) K, J2/kB=55(5) K and a ferromagnetic J3/kB=-20(5) K, possibly as result of dz2} orbitals in the Cu-O bonds providing superexchange (SE) pathways with JSE=6.5 K. 相似文献
17.
Hakalla R 《Journal of Molecular Spectroscopy》2000,204(2):176-183
The 1-0, 1-1, and 1-2 bands of the 3A system of (13)CO (c(3)Pi-a(3)Pi) have been recorded for the first time, in the form of discharge emission spectra photographed at high resolution. Preliminary rotational analysis suggests that the v = 1 level of the c(3)Pi state is perturbed in a fashion similar to the v = 0 level, previously observed by Dabrowski et al. (1987. I. Dabrowski, M. Vervolet, and D. C. Wang, Can. J. Phys. 65, 1171-1177). Rotational combination differences from the 1720 measured lines have been used to obtain rotational constants for the v = 0-2 levels of the a(3)Pi state, using the Hamiltonian of Brown et al. (1979. J. M. Brown, E. A. Calbourn, J. K. G. Watson, and F. D. Wayne, J. Mol. Spectrosc. 74, 294-318). and the least squares formalism of Curl and Dane (1988. J. Mol. Spectrosc. 128, 406-412), as modified by Watson (1989. J. Mol. Spectrosc. 138, 302-308). Term values for the c(3)Pi, v = 1 level have then been obtained from the line frequencies, and a set of effective rotational constants for the c(3)Pi (v = 1) level of (13)CO has been derived. Copyright 2000 Academic Press. 相似文献
18.
Abulencia A Acosta D Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arguin JF Arisawa T Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Azzurri P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barnes VE Barnett BA Baroiant S Bartsch V Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Ben Haim E Benjamin D Beretvas A Beringer J Berry T Bhatti A Binkley M Bisello D Bishai M 《Physical review letters》2006,96(10):102002
19.
Hyperfine Interactions - Rotational J=1→J=0 transitions in muonic molecule, (3Heμd) J ++, in [(3Heμd)++,2e]–D and [(3Heμd)++,e]+–D collisions are considered. The... 相似文献
20.
Senent ML Smeyers YG Domínguez-Gómez R Arroyo A Fernández-Herrera S 《Journal of Molecular Spectroscopy》2000,203(2):209-215
The roto-torsional energy levels of HSSH and DSSD up to J = 20 are evaluated variationally with a Hamiltonian expressed in terms of internal coordinates. The kinetic and potential parameters are derived from ab initio calculations with full optimization of the geometry. The calculated levels are employed for the determination of the centrifugal distortion constants. HSSH is a near-prolate symmetric rotor. The most stable C(2) conformer, calculated with MP4(SDQ)/cc-pVQZ, exhibits a 90.55 degrees dihedral angle. For J = 0, the lowest energies of HSSH and DSSD are 413.4876 cm(-1) (n = 1), 798.0304 cm(-1) (n = 2) and 1151.5773 cm(-1) (n = 3), and 304.3185 cm(-1) (n = 1), 594.2919 cm(-1) (n = 2), and 869.3508 cm(-1) (n = 3), respectively. For J = 60, the ab initio calculations allow the reproduction of the anomalous type-K doubling predicted with perturbation theory. Copyright 2000 Academic Press. 相似文献