Investigation on 1.07 μm laser emission in Nd~（3＋）-doped sodium fluoroborate glasses

Spectroscopic and fluorescence properties of Nd 3+ ions in sodium fluoroborate(SFB) glasses were prepared and characterized through optical absorption,emission and decay measurements.The energy level analysis was carried out using free-ion Hamiltonian model.Experimental oscillator strengths were determined by measuring the area encompassed by the absorption peaks recorded for 1.0 mol.% Nd 3+-doped glasses.The Judd-Ofelt parameters(2,4,6) were used to evaluate the laser characteristic parameters such as radiative transition probability(A R),radiative decay time(τ R),fluorescence branching ratio(β R) and stimulated emission cross-section(σ e) for the 4 F 3/2 metastable state.The fluorescence spectra for different concentrations of Nd 3+ ions were recorded by exciting the samples at 514.5 nm Ar + ion laser.     

Effect of Different Ligand Field Strengths on the Oscillator Strengths of Lanthanide Ions

ＥｆｅｃｔｏｆＤｉｆｅｒｅｎｔＬｉｇａｎｄＦｉｅｌｄＳｔｒｅｎｇｔｈｓｏｎｔｈｅＯｓｃｉｌａｔｏｒＳｔｒｅｎｇｔｈｓｏｆＬａｎｔｈａｎｉｄｅＩｏｎｓＷｕＤｅｎｇｇｕｏ（武登国），ＳｕｎＹｕａｎｈｏｎｇ（孙元洪），ＬｉＧｕｏｚｈｕ（李国柱）（Ｄｅｐａｒ...     

氧化钕和氧化镨钕在大气中的吸水特性研究

研究了氧化钕和氧化镨钕的吸水特性及吸水稳定后物质的结构与形态表征,通过增重试验及增重稳定后物质的X射线衍射试验,讨论了氧化钕和氧化镨钕吸水的一般动力学过程,并分析了影响吸水速率的因素。研究表明,氧化钕和氧化镨钕的吸水过程为未反应核模型,Lageren准一级、HO准二级动力学方程仅能对其诱导期之后的某个阶段拟合较好。氧化镨钕明显异于氧化钕,吸水产物孔隙率减小,吸一定水后出现类似"饱和"的现象。     

Nd2O3-NdF3-LiF熔盐体系中电导率及钕溶解度的测定

研究了Nd2O3-NdF3-LiF熔盐体系中电导率及钕的溶解度，并根据实验数据拟合了回归方程，分析TN度、LiF浓度、Nd2O3浓度对两种物理性质的影响。结果表明，升高温度，提高LiF浓度以及降低Nd2O3浓度可以提高熔盐体系的电导率；而降低温度，降低LiF浓度以及提高Nd2O3浓度可以减少钕在熔盐中的溶解度。所得研究结果可为电解氟盐法生产钕选择合理的电解质成分提供依据。     

Evaluation of biological effects of three neodymium compounds on silkworm,Bombyx mori

Neodymium (Nd) is one of the most famous members of rare earth elements family. With the increasing global demand for Nd, it can inevitably enter the environment and affect the ecological environment through the food chain and other ways. Therefore, it is very important to study the biological effects of Nd. In this study, the biological effects of 3 kinds of Nd compounds, i.e. neodymium oxide (Nd₂O₃), neodymium chloride (NdCl₃) and neodymium nitrate (Nd(NO₃)₃), were evaluated by using silkworm models through the method of intravascular injection. Each of the three Nd compounds was prepared into 6 groups at different concentrations (40, 50, 60, 70, 80, 90 μg/μL). The results show that within the certain concentration range, Nd compounds show great damage to the growth of silkworms since high death rate is observed: the death rate from Nd₂O₃ group is floating between 30% and 80%, the one from NdCl₃ group is between 17% and 33% and that from Nd(NO₃)₃ group is between 23% and 37%. It also reveals that Nd compounds have some negative effects on the body length and weight of silkworms. However, the histophysiological study shows that the three Nd compounds cause no obvious negative effects on the cell morphologies in midgut, fat body and silk gland. The XRD and FTIR spectra show that the secondary and the crystalline structures of silks are not destroyed, the TGA and DTG data exhibit that the thermal stability of silks is not damaged, and the tensile test shows that the mechanical properties of silks are not affected significantly by the intake of Nd compounds. In general, the intake of Nd compounds has significant inhibitory effects on silkworm growth but little negative impact on silk structures or cell morphology, the study can provide useful toxicological data for the safe application of Nd compounds in various fields.     

Novel High Rate Lithium Intercalation Cathode Materials

In recent years,energy storage devices with bothhigh energy and high power densities have been vigor-ously developed for an application to electric vehicles(EVs).The battery properties of ca.2kW·kg-1ofpower density and ca.15Wh·kg-1of energy densityare needed for the EV′s application in the future[1].As the electrode materials are basic elements for thebattery device,the cathode electrodes should have su-perior properties to above expected ones.One ap-proachto develop the cathode materials…     

Optical-transition properties of the Nd3+ ion in KLu(WO4)2 crystal

Optical absorption and emission intensities of Nd3+ ion in KLu(WO4)2 crystal were investigated. Based on the Judd-Offelt theory, we calculated the following spectral parameters: phenomenological intensity parameters Ω2=5.567×10–20, Ω4=3.597×10–20, and Ω6= 3.800×10–20 cm2. The radiative lifetime of levels 4F3/2 was 182.58 μs. The fluorescence branching ratio for the transition 4F3/2→4I11/2 was 46.98%. In addition, the radiative transition probabilities AJ,J’, oscillator strengths PJ,J’ and the values of inte...     

Spectroscopic Properties of Nd^3＋ -Doped High Silica Glass Prepared by Sintering Porous Glass

A new kind of Nd^3＋-doped high silica glass （SiO2 〉 96% （mass fraction）） was obtained by sintering porous glass impregnated with Nd^3 ＋ ions. The absorption and luminescence properties of high silica glass doped with different Nd^3 ＋ concentrations were studied. The intensity parameters Ωt （t = 2, 4, 6）, spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd^3＋ concentration in high silica glass was 0.27% （mole fraction） because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd^3 ＋- doped oxide glasses and commercial silicate glasses, the Nd^3 ＋ -doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.     

Nd(III)在NaF-KF熔盐钨电极上电化学行为

钕铁硼磁体中稀土元素钕占据较大比重,从钕铁硼废料回收稀土有重大意义。为进一步了解钕在高温下氟化物熔盐的行为,本文在1 063 K采用NaF-KF(摩尔比2:3)电解质体系,加入质量分数为1%的NdF₃,以Pt为参比电极,钨棒为对电极,用循环伏安法等电化学暂态测试研究了Nd(III)在惰性钨电极上的电化学过程,探究Nd(III)的还原机理。结果显示:Nd(III)于NaF-KF-NdF₃熔盐中在惰性钨电极上的电化学还原过程是受扩散控制的不可逆的一步反应:Nd(III)+3e-=Nd,1 063 K时循环伏安法得到Nd(III)的扩散系数为2.107×10-5 cm2/s,钕的成核机制为瞬时成核。      

Investigation of the structure of neodymium-di-(2-ethylhexyl) phosphoric acid combinations using electrospray ionization and matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance spectroscopy

Neodymium-di-(2-ethylhexyl) phosphoric acid (DEHPA) species forming in the organic phase during solvent extraction of neodymium with solutions of DEHPA have been studied. Two samples were prepared: one with a low molar ratio of neodymium to DEHPA, which is liquid and clear, and the other with a high molar ratio of neodymium to DEHPA (complete loading), which has the consistency of a gel. Electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric investigations show numerous compounds, in addition to the generally assumed species dimeric DEHPA and Nd(DEHP-DEHPA)₃, in the liquid sample. The nuclear magnetic resonance (NMR) spectroscopic investigation of pure DEHPA and of completely loaded sample confirm the formula of pure DEHPA and of the organic part of Nd(DEHP)₃. Furthermore, chemical analysis of a dried, completely loaded sample also proves the existence of the species Nd(DEHP)₃. Results of X-ray powder diffraction measurements of this sample agree well with literature data.     

Growth and characterization of new laser crystal Nda3＋：ca2.85Gd0.1（VO4）2

The crystal growth, crystal defect, thermal properties and luminescence properties of Nd3+:Ca2.85Gd0.1(VO4)2 were investigated. Nd3+:Ca2.85Gd0.1(VO4)2 crystal grown by Czochraski method was green colored, and was not transparent, which was possibly due to residual impurities in V2O5, or due to the lack of oxygen in the growth process. And the Nd3+:Ca2.85Gd0.1(VO4)2 crystal had the existence of 180° do-mains. However, the annealing method could effectively decrease the crystal defect and greatly improve the quality of crystal. The average thermal expansion coefficients calculated were α⊥c=9.5767×10-6 K-1, α∥c=10.7647×10-6 K-1, respectively. The specific heat of Ca2.85Gd0.1(VO4)2 was 0.401 J/(g·K) at 330 K. The polarized absorption spectra and the polarized fluorescence spectra of Ca2.85Gd0.1(VO4)2 were measured at 330 K. Based on the Judd-Ofelt theory, the intensity parameter Ωλ (λ=2, 4, and 6), the radiation transition probabilities τrad, the stimulated-emission cross section σp in Nd3+:Ca2.85Gd0.1(VO4)2 crystal were calculated.     

Synthesis of Polycrystalline Nd∶YAG Nanopowders Used for Sintering Transparent Ceramics via Gel Combustion

Polycrystalline nano-sized neodymium doped yttrium aluminum garnet (Nd∶Y3Al5O12, Nd∶YAG) powders were synthesized via a gel combustion method using nitrates and citric acid as starting materials. The evolution of phase composition and micro-structure of the powders were characterized by X-ray powder diffraction, thermogravimetry/differential thermal analysis and scanning electron microscopy. Well-crystallized Nd∶YAG nano-sized powders could be obtained at 950 ℃ for 2 h. The resultant powders are well dispersed, have a relatively narrow size distribution with an average particle size of approximately 50 nm, and show excellent sinterability. These powders can be densified to 99.2% of the theoretical density by HP sintering at 1700 ℃ for 3 h under 20 MPa nitrogen pressure.     

Optical properties and radiative rates of Nd3+ doped zinc-sodium phosphate glasses

Preparation using melt quenching technique and optical characterizations of Nd~(3+) doped Zn-Na phosphate glasses are presented. The structure of the present glasses was studied using X-ray diffraction and FT-IR spectroscopy. UV-vis spectra of the present glasses were analyzed at different concentrations of Nd_2 O_3. The effect of neodymium concentration on the density and energy band gap was investigated. The density of the present glasses slightly increases with the increasing of Nd_2 O_3. A small variation of energy band gap with the increasing of neodymium content is observed as well, while E_g values decrease with the increase of Nd_2 O_3 content. The E_g values lie between 4.36 and 4.69 eV. Based on the measured optical spectra, Judd-Ofelt theory was used to determine the optical parameters such as line strengths, optical intensity parameters(Ω_t), transition probabilities, and transition lifetimes. Hypersensitive transitions were identified in the absorption spectrum, the greatest line strengths are recorded at the transitions~2 G_(7/2)+ ~4 G_(5/2), ~4 S_(3/2) + ~4 F_(7/2) and ~4 D_(1/2) + ~4 D_(3/2)+ ~4 D_(5/2) + ~2 I_(11/2) with wavelengths of 580, 475 and 355 nm,respectively. Lifetimes of the important ~4 F_(3/2) laser-level were determined; which show decreasing trend with the increasing of Nd_2 O_3 content and are found to be between 0.838 and 1.595 ms. The uncertainty of the present results was estimated. The RMS deviations were determined, which show lower values than those in the literature.     

有机次膦酸在硝酸体系下提取稀土研究

本文采用溶剂萃取法,用有机次磷酸萃取剂从富含稀土元素镧(La）、钕(Nd）、钇(Y)、铈(Ce）的硝酸溶液中提取稀土。选择盐酸为反萃剂。考察了酸度、萃取剂浓度、相比和萃取时间对萃取率和反萃率的影响,结果表明,二异丁基膦酸萃取稀土的最佳条件为：室温,酸度0.2mol/l,萃取剂浓度40%,A/O比1:5,萃取时间15min,镧（La）、钕（Nd）,铈（Ce）和钇（Y）分别为41.68%、81.30%、81.29%和100%。当利用盐酸作为反萃实验的反萃剂时其最佳条件为：室温,初始水相稀土溶液为0.3 mol/L,反萃剂盐酸为6 mol/L,负载有机相与反萃剂盐酸溶液的体积比为1:6,将反萃的震荡时间改变为5min,应用上述条件的镧(La）、钕(Nd）、铈(Ce）、钇(Y)的反萃率分别为92.45%、94.88%、95.76%、93.34%。有机次膦酸对稀土元素（La）、钕（Nd）、铈（Ce）和钇（Y）的萃取效率不同。钇的提取率高于镧、钕和铈。它是一种有机次膦酸,对轻稀土元素亲和力低,对重稀土元素亲和力强。     

Growth and optical properties of Pr~(3+):La_2CaB_(10)O_(19) crystal

Pr3+ doped La2CaB10O19 crystal were grown by the top-seeded solution growth(TSSG) method.The absorption spectra,emission spectra and lifetime were measured at room temperature.The J-O parameters(Ωt,t=2,4,6),the radiative transition probabilities AJ,J',oscillator strengths PJ,J',radiative lifetime τ,fluorescence branch ratios βJ and the value of integrated emission cross section have also been calculated.Five main absorption bands,3H4 to 3P1+3P2,3P0,1D2,3F3 + 3F4 and 3F2,were observed in the absorption spect...     

Spectroscopic study of the Pr-doped BiBO glass and Ca4GdO（BO3）3 single crystals

Detailed spectroscopic studies of Pr³⁺ ions in BiBO glass and Ca₄GdO(BO₃)₃ crystal were performed. Experimental absorption spectra were measured at room temperature and assigned. The first principles discrete variational multielectron method was used to model the polarized absorption spectra of the Ca₄GdO(BO₃)₃:Pr³⁺; without any fitting parameters, the overall appearance of the spectra was reproduced satisfactorily. The energy intervals between different molecular orbitals in the [PrO₆] cluster were estimated. The conventional Judd-Ofelt theory was used to calculate the oscillator strengths of the 4f-4f transitions in the BiBO:Pr³⁺ system; the set of the phenomenological intensity parameters was determined.     

Mechanisms of Enhancement of Photocatalytic Properties and Activity of Nd^3＋ -Doped TiO2 for Methyl Orange Degradation

Nd^3 -doped TiO2 powders were prepared by the sol-gel method. Their crystal pattern and parameter, the specific surface area, the surface chemical state of Ti and the ratio of O/Ti were characterized. The results show that Nd impurity hinders the crystal transformation, and decreases the relative intensity of (101) peak. The crystallite sizes of Nd^3 -doped TiO2 powders decrease while their specific surface area increase owing to the Nd^3 doping. The XPS measurement shows that the content of Ti (Ⅲ) and ratio of O/Ti on their surfaces increase significantly with the increase of Nd^3 dosage. The adsorption and photodegradation experiments show that the optimum molar content of Nd^3 is 1.2%.     

金属钕及氧化钕中稀土杂质光谱测定

在色散０．２５ｍｍ／ｍｍ光栅光谱仪上，以控制气氛直流电弧粉末地测定了金属钕及氧化钕中氧化镧、氧化铈、氧化镨、氧化钐、氧化钆、氧化镝和氧化钇。采用正交设计实验，确定了测定条件。测定的下限对氧化铈、氧化镨为０．０５％，氧化镧、氧化钐、氧化钆、氧化镝和氧化钇为０．０３％，相对标准偏差为６％￣１８％。     

氯化钕与甘氨酸配位反应的热化学研究

采用具有恒温环境的反应热量计,以2mol     

Hydrothermal synthesis and crystal structure study of two novel 3-D mellitates {Nd2[C6(COO)6](H2O)6} and {Ho2[C6(COO)6](H2O)6}

Two novel 3-D coordination compounds, Nd2[C6(COO)6](H2O)6(1)and Ho2[C6(COO)6](H2O)6(2), were hydrothermally synthe-sized from mellitic acid and neodymium perchlorate (or holmium perchlorate) in the alkaline aqueous solution and characterized with ele-mental analysis, TG, IR spectrum, and single crystal X-ray diffraction. The two compounds were isostructural and crystallized in the ortho-rhombic system, space group Pnnm, with a=1.3531 (4) nm, b=0.6687 (2) nm, c=1.0224(3) nm, V=0.92523(5) nm3, Z=4, D=2.630 g/cm3, F(000)=696.0, Goof=1.052. Final R indices [I 2Σ(I)]: R1=0.0195, wR2=0.0382 for 1; a=1.3411(2) nm, b=0.6586(1) nm, c=1.0116(2) nm, V=0.8935(3) nm3, Z=4, D=2.877 g/cm3, F(000)=724.0, Goof=1.061. Final R indices [I 2Σ(I)]: R1=0.0200, wR2=0.0479 for 2. In the two compounds 1 and 2, the mellitic acid ligand, in which all the carboxylate groups were deprotonated, had only one kind of coordination mode to bridge metal ions to form four-connected three-dimensional diamondiod networks.