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本文通过分析不同几何配置下的偏振拉曼光谱对非线性光学晶体的晶格振动模式进行了研究. 首先根据因子群分析,将晶体的振动模按晶体对称群的不可约表示进行分类,其次测量了晶体在10–1600 cm-1范围内,不同几何配置下的偏振拉曼光谱,并在此基础上指认了晶体的晶格振动模式. 300 cm-1以下的振动峰,归结为晶体的外振动,来自[BiO6],[ZnO4],[BO4]和[BO3]原子基团的平动和转动;300cm-1以上为晶体的内振动,主要与Bi-O,和Zn-O键振动有关. 晶体拉曼光谱中最高振动频率达到1407 cm-1,被指认为[BO3]三角形中B-O键的伸缩振动,体现了[BO3]基团中高的电子非局域化程度.
关键词:
2ZnOB2O6单晶')" href="#">Bi2ZnOB2O6单晶
偏振拉曼光谱
振动模式 相似文献
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采用高温固相法,以CaCO3 (A.R)、BaCO3 (A.R)、H3BO3 (A.R)和Eu2O3 (99.99%)为原料制备了Ba2Ca(BO3)2∶Eu2+绿色发光材料,测量了材料的晶体结构、发光特性及色坐标等。Ba2Ca(BO3)2∶Eu2+材料的激发光谱覆盖200~500 nm的紫外-可见光区。在400 nm近紫外光激发下,材料的发射光谱为一主峰位于537 nm的非对称宽谱,对应于Eu2+的4f65d1→4f7特征跃迁。研究发现,随Eu2+掺杂浓度的增大,Ba2Ca-(BO3)2∶Eu2+材料的发射强度呈现先增大、后减小的变化趋势,最大发射强度对应的Eu2+掺杂摩尔分数为2%。造成发射强度下降的原因为浓度猝灭,其机理为电偶极-电偶极相互作用。依据晶格常数及实验光谱数据,得出临界距离Rc分别为2.64 nm和2.11 nm。随Eu2+掺杂浓度的增大,Ba2Ca(BO3)2∶Eu2+材料的色坐标变化微小。计算得到Ba2Ca(BO3)2∶2%Eu2+的转换效率约为72%。 相似文献
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通过偏振拉曼光谱和第一性原理计算对非线性光学晶体BaBPO5的 晶格振动模式进行了研究. 实验得到了不同几何配置下、在100–1600 cm-1范围内的晶体偏振拉曼光 谱与傅里叶变换红外吸收谱, 结合因子群分析方法研究了晶体的外振动与内振动模式特征. 分析表明拉曼振动主要来自于PO4四面体和BO4四面体的振动, 且PO4基团振动具有较强的拉曼与红外活性. 此外,根据第一性原理对晶体拉曼振动进行了数值模拟, 进一步明确了拉曼峰与晶体中原子振动的对应关系, 计算表明拉曼光谱中位于672 cm-1峰位来自晶体中B–O–P键的伸缩振动, 这是晶体中PO4四面体和BO4四面体共顶点连接的特征结构在光谱中的体现. 相似文献
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采用高温固相法制备了Sr3Gd0.5-xTb0.5(BO3)3∶xEu3+系列荧光粉,并研究了其发光性质与能量传递过程。Sr3Gd0.5-xTb0.5(BO3)3∶xEu3+系列荧光粉在300~400 nm的近紫外光有效激发下产生489,544,594,614,624 nm的发射谱线,分别对应于Tb3+和Eu3+的特征跃迁。荧光寿命测试表明,随着Eu3+掺杂浓度的增大,Tb3+寿命逐渐缩短,证实该体系中存在Tb3+→Eu3+的能量传递过程,能量传递效率最大值为20.53%。在对Tb3+和Eu3+的能级结构进行分析的基础上,进一步探讨了Tb3+→Eu3+能量传递过程。Sr3Gd0.5-xTb0.5-(BO3)3∶xEu3+系列荧光粉具有良好的红色发光性质,是潜在的可以应用于白光LED的光转换材料。 相似文献
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Guochun Zhang Yicheng WuPeizhen Fu Guofu WangHongjun Liu Guo FanChuangtian Chen 《Journal of Physics and Chemistry of Solids》2002,63(1):145-149
A new sodium samarium borate with composition Na3Sm2(BO3)3 (NSBO) has been synthesized by high temperature solid state reaction. The yellowish transparent single crystals of Na3Sm2(BO3)3 have been grown from the Na2CO3-H3BO3 flux system using the top-seeded solution growth (TSSG) method. X-ray diffraction analysis demonstrated that the NSBO crystals belong to orthorhombic systems and lattice parameters are a=5.0585 Å, b=11.0421 Å, c=7.0316 Å. The measurement of the infrared spectrum indicated that the basic anionic groups are the BO3−3 groups. Furthermore, Na3Sm2(BO3)3 exhibits an optical second harmonic generation effect which is close to that of KDP (KH2PO4). 相似文献
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V. E. Harutunian K. N. Kocharian R. M. Martirosian V. D. Voronkov L. N. Bezmaternich 《International Journal of Infrared and Millimeter Waves》1989,10(7):841-845
AFMR in Fe3 BO6 is investigated by quasioptical method in submillimeter-wave band. Depending on conditions of excitation two resonance modes were observed. One mode, which is identified as a quasiferromagnetic, was investigated both in phases 1 and 1. Also the quasiantiferromagnetic AFMR mode was observed and investigated. The carried researches evidence in favour of two-sublattice Fe3 BO6 model. 相似文献
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Vacuum ultraviolet (VUV) excitation and photoluminescence (PL) characteristics of Eu3+ ion doped borate phosphors; BaZr(BO3)2:Eu3+ and SrAl2B2O7:Eu3+ are studied. The excitation spectra show strong absorption in the VUV region with the absorption band edge at ca. 200 nm for BaZr(BO3)2:Eu3+ and 183 nm for SrAl2B2O7:Eu3+, respectively, which ensures the efficient absorption of the Xe plasma emission lines. In BaZr(BO3)2:Eu3+, the charge transfer band of Eu3+ does not appear strongly in the excitation spectrum, which can be enhanced by co-doping Al3+ ion into the BaZr(BO3)2 lattices. The luminescence intensity of BaZr(BO3)2:Eu3+ is also increased by Al3+ incorporation into the lattices. The PL spectra show the strongest emission at 615 nm corresponding to the electric dipole 5D0→7F2 transition of Eu3+ in both BaZr(BO3)2 and SrAl2B2O7, similar to that in YAl3(BO3)4, which results in a good color purity for display applications. 相似文献
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Yu.V. KnyazevN.B. Ivanova N.V. Kazak M.S. PlatunovL.N. Bezmaternykh D.А. Velikanov А.D. Vasiliev S.G. Ovchinnikov G.Yu. Yurkin 《Journal of magnetism and magnetic materials》2012,324(6):923-927
The needle shape single crystals Co3−x MnxO2BO3 with ludwigite structure have been prepared. According to the X-ray diffraction data the preferable character of distinct crystallographic positions occupation by Mn ions is established. Magnetization field and temperature dependencies are measured. Paramagnetic Curie temperature value Θ=−100 K points out the predominance of antiferromagnetic interactions. Spin-glass magnetic ordering takes the onset at TN=41 K. The crystallographic and magnetic properties of Co3O2BO3:Mn are compared with the same for the isostructural analogs Co3O2BO3 and CoO2BO3:Fe. 相似文献
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The magnetic properties of trigonal Nd0.9Dy0.1Fe3(BO3)4 substituted compound with the competitive Nd-Fe and Dy-Fe exchange interactions have been investigated. It has been shown that in Nd0.9Dy0.1Fe3(BO3)4 a spontaneous spin-reorientation transition from an ease-axis state to an easy-plane occurs near 8 K. Anomalies of the magnetization curves are observed in a spin-flop transition induced by the magnetic field B‖c. The calculations were performed using a molecular-field approximation and a crystal-field model for the rare-earth subsystem. Extensive experimental data on the magnetic properties of Nd0.9Dy0.1Fe3(BO3)4 have been interpreted and good agreement between theory and experiment has been achieved using the obtained theoretical dependences. 相似文献
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Gurinder Pal SinghSimranpreet Kaur Parvinder KaurD.P. Singh 《Physica B: Condensed Matter》2012,407(8):1250-1255
The structural and optical analysis of glasses is carried out by XRD, FTIR, density and UV visible spectroscopic measurement techniques. XRD results have confirmed the glassy nature of the samples. The FTIR spectral analysis reveals that with the combined presence of ZnO and CeO2 contents in Al2O3-PbO-B2O3 glasses, more BO3 groups are transformed into BO4. The optical analysis reveals that optical band gap energy decreases more for CeO2-ZnO-Al2O3-PbO-B2O3 glasses (from 2.28 to 1.84 eV). The presence of CeO2 and ZnO in the glass samples causes more compaction of the borate network due to the formation of more BO4 groups and the presence of ZnO4 groups, which results an increase in density, refractive index and decrease of molar volume. 相似文献
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Temperature-dependent high-resolution optical spectra of the Er3+ probe ion in DyFe3(BO3)4 and HoFe3(BO3)4 are reported. The data provide the temperature of magnetic ordering and direction of the Fe3+ magnetic moments. Both compounds order magnetically at TN=39±1 K. The magnetic structure of DyFe3(BO3)4 is of the easy-axis type, while that of HoFe3(BO3)4 is of the easy-plane type. The role of anisotropic interactions between the iron and the rare-earth subsystems is discussed. 相似文献
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Raman scattering by phonons and by magnon pairs has been observed in Fe3BO6. Of the predicted 60 Raman-active modes, 39 have been identified and classified according to their symmetries. The two-magnon band shows a strong decrease in intensity with increasing temperature, and almost vanishes close to TN = 508 K. The origin of this effect is attributed to the existence of a nearly dispersionless magnon branch. 相似文献
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Pure and WO3 doped CeO2-PbO-B2O3 glasses are prepared by the melt-quench technique. The structural and optical analyses of glasses are carried out by XRD, FTIR, density and UV-vis spectroscopic measurement techniques. FTIR analysis indicates the transformation of structural units of BO3 into BO4 with W-O-W vibration and the presence of WO4 and WO6 units observed with increase in WO3 contents. Decrease in band gap for CeO2-PbO-B2O3 glasses from 2.89 to 2.30 eV and for WO3 doped glasses from 2.89 to 1.95 eV has been observed and discussed. This decrease in band gap with WO3 doping approaches to semiconductor behavior. It shows that the presence of WO3 in the glass samples causes more compaction of the borate network due to the formation of BO4 groups and the presence of WO4 and WO6 groups, which result in a decrease in the optical band gap energy and increase in the density. 相似文献