ICP-AES法测定铜稀土合金中的稀土元素

本文采用硝酸溶解试样,制成试样浓度为０．５－１ｍｇ／ｍＬ,盐酸浓度为１０％（Ｖ／Ｖ）的溶液,ＩＣＰ－ＡＥＳ法直接测定铜稀土含金中０．０５％￣１０％的单一稀土元素。研究了铜基体及其他元素干扰,选择了合适的分析线,优化了测定条件。方法准确,简单,快速,已用于铜稀土合金研究中的样品分析。     

Applications and functions of rare-earth ions in perovskite solar cells

The emerging perovskite solar cells have been recognized as one of the most promising new-generation photovoltaic technologies owing to their potential of high efficiency and low production cost. However, the current perovskite solar cells suffer from some obstacles such as non-radiative charge recombination, mismatched absorption, light induced degradation for the further improvement of the power conversion efficiency and operational stability towards practical application. The rare-earth elements have been recently employed to effectively overcome these drawbacks according to their unique photophysical properties. Herein, the recent progress of the application of rare-earth ions and their functions in perovskite solar cells were systematically reviewed. As it was revealed that the rare-earth ions can be coupled with both charge transport metal oxides and photosensitive perovskites to regulate the thin film formation, and the rare-earth ions are embedded either substitutionally into the crystal lattices to adjust the optoelectronic properties and phase structure, or interstitially at grain boundaries and surface for effective defect passivation. In addition, the reversible oxidation and reduction potential of rare-earth ions can prevent the reduction and oxidation of the targeted materials. Moreover, owing to the presence of numerous energetic transition orbits, the rare-earth elements can convert low-energy infrared photons or high-energy ultraviolet photons into perovskite responsive visible light, to extend spectral response range and avoid high-energy light damage. Therefore, the incorporation of rare-earth elements into the perovskite solar cells have demonstrated promising potentials to simultaneously boost the device efficiency and stability.     

Photoluminescence spectra of intracenter 4f transitions of rare-earth metal dopants in crystalline ZnO films

The influence of annealing in the medium of an ionized nitrogen, additionally introduced impurities, and regimes of post-growth annealing on photoluminescence spectra of intracenter 4f transitions of rare-earth metal dopants (Ce, Eu, Sm, Er, Tm, Yb) in crystalline ZnO films has been investigated. The films have been prepared using molecular-beam epitaxial growth and magnetron sputtering. According to the X-ray diffraction analysis, the films have a single-crystal structure. It has been shown that the annealing in the medium of an ionized nitrogen, regardless of the method used for producing the ZnO films, leads to significant changes in the photoluminescence spectrum, i.e., to a decrease in the emission intensity and a shift in the position of the emission maximum toward the long-wavelength range of the spectrum. The nitrogen concentration has been determined by the nuclear reaction method. It has been revealed that the spectra contain intense emission lines due to the intracenter 4f transitions of rare-earth elements (Sm, Er, Tm, Yb) in the crystalline ZnO films prepared by magnetron sputtering, and the intensity of the emission lines increases upon introduction of codopants, namely, Ce and Er.     

ICP－AES法同时测定岩石、矿物、土壤等样品中十五种稀土元素的方法研究

本文应用强酸Ｉ号离子交换树脂将稀土元素与基体元素分离，待测液直接用ＩＣＰ－ＡＥＳ同时测定１５种稀土元素，测定中采用干扰等效浓度法，消除稀土元素之间和残余基体元素产生的光谱干扰，方法具有较高的准确度和精密度，是目前较理想的测定岩石等样品中微量稀土元素的方法。     

Spectral analysis of rare-earth elements in ash of sapropel and its fractions

Quantitative atomic emission spectral analysis was used to study the rare-earth content in sapropel and the rare-earth distribution over the isolated fractions. The conditions for determination of Ce, Y, and La (analytical lines, arc discharge current, exposure time) were selected empirically. We calculated the metrological characteristics of the proposed technique. We have shown that in Tyurin fractionation, the nonhydrolyzable residue fraction has the highest concentrations of these elements. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 273–276, March–April, 2009.     

稀土元素La对Ni75B17Si8非晶合金形成能力和热稳定性的影响

本文发现微量稀土元素在某些合金中可不呈均匀固溶态分布,而与母合金某些原子反应生成高熔点化合物,或吸附于合金中异质核心表面改变其异质形核的活性。当稀土元素以这种状态存在时,不但失去稳定非晶相的作用,而且促进异质形核,降低合金的非晶形成能力和热稳定性。 关键词：     

Optical properties of iron alloys with heavy rare-earth elements

Spectral-ellipsometric measurements by the Beatty method were made in the region from 1 eV to 4 eV at temperatures of 100, 293, and 700 K to determine the relation between the distinctive features of the optical absorption spectrum and the principal parameters of the electron energy spectrum in iron alloys with rare-earth elements. The fundamental bands of interband optical absorption of Fe₂-R alloys (R=Gd, Ho, Er) in the region 2.8–3.1 eV are formed by indirect transitions from d-like states, which are genetically bound to 3d–5d electrons of the transition metal and the rare-earth metal, in a state above the Fermi level.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 64–67, December, 1988.We thank our senior research colleague V. A. Domyshev for supplying the samples and carrying out the x-ray structure analysis.     

Spectroscopic manifestations of random lattice deformations in rare-earth doped crystals

The inhomogeneous broadening of a zero-phonon line of an optical transition between nondegenerate and degenerate levels of a rare-earth impurity center in a crystal that is caused by random lattice deformations has been considered. Spectra of non-Kramers and Kramers rare-earth ions located at tetragonal and cubic sites have been investigated. Lines of a characteristic shape with a deep dip in the center have been detected.     

Effect of copper and cobalt impurities on the electronic structure and optical spectra of the intermetallic compound PrNi5

The electronic structure and optical properties of the intermetallic compound PrNi₅ and their evolution during the substitution of copper or cobalt atoms for nickel atoms have been investigated. The band spectra of the studied compounds have been calculated in the local spin density approximation corrected to account for strong electron-electron interactions in the 4f shell of the rare-earth ion (LSDA + U method). The dispersion relations of the optical conductivity in the interband light absorption region have been interpreted using the results of calculations of the electron density of states.     

稀土元素钐的光电流光谱

利用光电流信号研究了稀土素钐的原子光谱。钐原子被染科激光（由氩离子激光泵浦若丹明６Ｇ）激发。实验中探测了从６０８．０００－６２１．０００ｎｍ的大约２０条谱线，对其中大部分谱线作了指认，发现了一些新谱线。对钐原子中光电流信号的正，负特性作了讨论。     

Collisional broadening and shifting of ammonia absorption lines at 790 nm

By using a diode laser spectrometer based on a commercial heterostructure diode laser operating in free-running mode, line shape parameters of some ammonia ro-vibrational overtones at 790 nm have been measured at room temperature. These weak absorption lines have been detected by using the wavelength modulation spectroscopy technique with second-harmonic detection. The broadening and shifting coefficients have been obtained for ten absorption lines by fitting the collected second-harmonic absorption features and varying the pressure of different buffer gases. Received 13 February 2002 / Received in final form 18 September 2002 Published online 17 December 2002 RID="a" ID="a"e-mail: alex@ifam.pi.cnr.it     

Diode laser spectroscopy of overtone bands of acetylene

Overtone absorption lines of acetylene in the regions around 12700 and 11800 cm^–1 have been examined by the use of tunable diode lasers in free-running mode. The diode laser emission wavelength was scanned around the gas resonances by simply sweeping its injection current, permitting a direct observation of the absorption line-shapes. Weak overtone absorption lines have been detected by using the wavelength modulation (WM) spectroscopy with 2nd harmonic detection technique and the collisional broadening and shift coefficients have been obtained. The high resolving power and accuracy of the spectrometer permitted a wavenumber error of less than 0.01 cm^–1. The correct interpretation of the absorption signals when detecting the second harmonic in the presence of a sloping background is discussed.     

Features of the local structure of rare-earth dodecaborides RB12 (R = Ho, Er, Tm, Yb, Lu)

The parameters of the local crystal structure of dodecaborides RB₁₂ (R = Ho, Er, Tm, Yb, Lu) have been determined by extended X-ray absorption fine structure (EXAFS) spectroscopy. It has been shown that the vibrations of the rare-earth ion with respect to the boron cage are well described in the harmonic approximation. At the same time, the displacement of rare-earth ions from equilibrium positions of the crystal structure should be taken into account to determine the length of the R-B bond. The analysis of EXAFS spectra has revealed the displacement of 1–6% of rare-earth ions by about 0.2–0.3 Å in all compounds under investigation; this displacement at low temperatures results in the formation of a cage glass phase.     

Effective nuclear charge approximation for free rare-earth ions

A semi-empirical method to describe the electron structure of free many-electron rare-earth ions has been proposed. The method takes into account the spin–orbit interaction as well as relativistic interactions known as Breit’s terms. It is shown that a set of parameters to calculate the electronic spectrum of a free rare-earth ion with accuracy less than 5% can be limited to an effective nuclear charge of the rare-earth ion and a constant related to the Breit’s terms. Using the known experimental spectra of free rare-earth metals these parameters have been calculated for basic terms of all rare-earth ions.     

杂质元素特征X射线对氢气放电源打靶新谱线的影响

 在氢气放电源打靶的实验中,测到了系列能量恒定不变的低能X射线新谱线,这些新谱线的能量分别为(1.70±0.10) keV, (2.25±0.07) keV,(2.56±0.08) keV,(3.25±0.10) keV和（3.62±0.11） keV,与Si,Ta,S,Cl,K和Ca等元素的特征X射线能量相近,但靶中所含的杂质或来自放电室的杂质元素可能会产生这些能量的X射线谱峰,证实新谱线是否由这些元素的特征X射线干扰所致显得尤为重要。分析了本实验系统中各种杂质的可能来源,论证了放电室端杂质对新谱线的影响,及靶材料中体杂质和面杂质对新谱线的影响;用X射线光电子能谱仪对靶做了表面分析。研究结果表明：杂质元素的特征X射线不会对氢气放电源打靶产生的新谱线有影响。这些新谱线的性质有待进一步的实验研究。     

151Eu Mössbauer parameters in rare earth oxides LnEuO3 and EuLnO3, synthesized by high pressure

Abstract

The ¹⁵¹Eu double-rare-earth oxides LnEuO₃, (Ln = light rare-earth elements) and EuLnO₃, (Ln = heavy rare-earth elements) which were synthesized by means of high pressure and high temperature for the first time were investigated using Mossbauer spectroscopy. Considering the asymmetric factor + 0, the ¹⁵¹Eu Mossbauer spectra were fitted by twelve transition lines. Results show that the isomer shifts of ¹⁵¹Eu increase in a linear fashion with increasing one-formula-unit volume v₀ of the oxides because of the lanthanide contraction. The slopes being different for the light and heavy elements.     

Über das Verhalten der 4f-Elektronen in einigen Metallen der Seltenen Erden unter der Einwirkung von Licht

The visible spectra of the rare-earth metals Pr, Nd, Sm, and Er were examined whether they contain absorption lines due to transitions within the 4f-shell. Optical measurements were made on vacuum evaporated transparent films at 90° K. No spectral lines were found. It was shown by complete oxydation of the metal films that eventual absorption lines of the metals must be at least 3.5 times weaker or broader than those of the oxydes. The missing of the lines is suggested to be caused by the conduction electrons: 1. As the crystalline field is largely screened by the conduction electrons the oscillator strength of the electric dipole radiation is rigorously reduced. 2. Lines may be broadened by exchange of excitation between 4f-electrons and conduction electrons.     

中子、γ射线在稀土-高分子材料中的输运(英文)

为研究新型复合屏蔽材料的最佳厚度与各种成分最佳配比, 用MCNP计算了中子、 γ射线在稀土 高分子与重金属复合材料中的通量。 对中子、 γ射线在屏蔽体中变化规律进行了深入探索, 同传统复合屏蔽材料的屏蔽性能进行了对比。 结果表明, 中子和γ射线通过屏蔽体时, 其强度遵循指数衰减规律。 新型屏蔽材料对中子的屏蔽效果均优于铅硼聚乙烯, 对γ射线的屏蔽效果均劣于W Ni合金, 且并非稀土含量越高, 材料对中子辐射屏蔽能力越强。 A series of shielding analyses have been performed to estimate the material composition and optimum thickness required for a new radiation shield with various rare earth doped polymer and heavy metal mixtures. The neutron and γ photon fluxes have been calculated by Monte Carlo N Particle(MCNP) transport code. The results indicate that the relative fluxes of γ photon and neutron in both traditional and new composite materials follow an exponential decay rule with the distance of penetration. It can be seen that the composite material consisting of rare earth doped polymer and heavy metal has stronger neutron shielding performance than lead boron polyethylene, but weaker γ shielding effectiveness than W Ni alloy. It is also found that materials with more components of rare earth elements don’t always provide better neutron shielding performance.     

H2O分子泛频振动谱的半导体激光检测

本文使用0.82μmAlGaAs激光二极管(LD)观测H_2O分子(0,0,0)—(2,1,1)泛频振动吸收谱,获得822.6～823.2 nm波长范围内H_2O分子26条泛频吸收谱线.其中,检测谱线的最小吸收系数α_(min)～3×10~(-6)cm(-1),对α～1×10~(-4)cm~(-1)谱线所获得的信噪比(SNR)约60.本文还观测了气体压强对泛频谱线形、线宽的影响,测量了泛频谱线的压强增宽系数β_p～0.128MHz/Pa.     

Satellite lines in the optical spectrum of Mn2+ in rare earth double nitrate crystals

Satellite lines have been observed in the spectra of Mn²⁺ in crystals of lanthanum manganese double nitrate and praseodymium manganese double nitrate doped with impurity ions on Mn²⁺ sites and rare-earth sites. The lattice sites in the neighbourhood of the Mn²⁺ ions which must be occupied by impurity ions to produce satellite lines have been identified. Besides the satellite lines a common line shift was observed, which was concentration dependent.Project of the Sonderforschungsbereich Festkörperspektroskopie Darmstadt-Frankfurt supported by the Deutsche Forschungsgemeinschaft.