Optische übergangswahrscheinlichkeiten der Konfigurationen 3p 5 4s–3p 5 5p des Argon I

Optical transition probabilities of the configurations 3p ⁵ 4s–3p ⁵ 5p of Argon I were determined in a wall-stabilized arc plasma and compared with the theoretical results for different types of spin-orbit-coupling. Mostly the differences in the results forLS-jl- and intermediate-coupling are small compared with the deviations of the experimental values. Therefore it may be presumed that in some cases not the assumption of an approximately valid coupling scheme is responsible for the errors of the theoretical transition probabilities, but the other quantum mechanical approximation processes.     

Phase Transition in the Compound NH3(CH2)5NH3TlCl5

Penthylene diammonium pentachlorothallate(III) exhibits a phase transition at 316 K <artwork name="GPHT21157eu1"> This transition has been characterized by optical birefringence, dielectric measurements differential scanning calorimetry and spectroscopic measurements on polycrystalline samples. The space group and the cell parameters of phase I were determined by X-ray diffraction from single crystals. Phase I has space group P2₁2₁2₁, with Z = 4, a = 7.696(3), b = 13.2890(17) and c = 13.503(18) Å. The transition is both displacive and order-disorder involving mainly conformational changes of the organic chain [NH₃(CH₂)₅NH₃]²⁺ coupled with distortion of the TlCl₆ octahedra. This behaviour and the crystal dynamics will be discussed and compared with those found in the literature for homologous compounds.     

Pressure effects on 2p5 3p - 2p5 3d transitions in neon

The collisional broadening and shift of four spectral lines of neon (747.2, 748.8, 753.5, 754.4 nm) arising from 2p⁵ 3p - 2p⁵ 3d transitions, emitted from a low-pressure glow discharge in pure neon and neon-helium mixtures have been measured using a Fabry-Perot interferometer. The values of pressure broadening and shift coefficients are determined and analyzed in terms of the impact theory.     

Photoelectric Phenomena in Au3In5Se9 and Au3Ga5Se9 Compounds

The anisotropy of photoconductivity in Au₃In₅Se₉ and Au₃Ga₅Se₉ crystals grown by the Bridgman method have been investigated as a function of temperature in the temperature range of 100 - 420 K. It is shown that the crystals have a wide range of spectral sensitivity of 0.9 - 1.8 eV. The width of the band gaps and their temperature coefficient are determined. The life time of the current carriers are determined at different levels of excitations.     

Lebensdauer des 5s5p 3 P 1-Zustands von Strontium

The lifetime of the 5s5p ³ P ₁ state of Sr has been determined with optical double resonance by observation ofrf-transitionsΔm _J =±1 between Zeeman levels of the even isotopes. The measurement yields the value τ(5³ P ₁, Sr)=2.1(3) · 10^?5 sec. A new type of narrowing of optical double resonance signals due to a time-of-flight effect of the radiating atom has been observed and compared with the theory.     

Infrared spectroscopy and lattice dynamical calculations of Gd3Al5O12, Tb3Al5O12 and Lu3Al5O12 single crystals

The infrared (IR) reflectance spectra of Gd₃Al₅O₁₂, Tb₃Al₅O₁₂ and Lu₃Al₅O₁₂ single crystals are studied for the first time. At room temperature, 15 infrared active modes for Lu₃Al₅O₁₂ and 14 for Gd₃Al₅O₁₂, Tb₃Al₅O₁₂, out of the 17 theoretically predicted, have been experimentally recorded. The complex dielectric function the refractive index, the absorption coefficient as well as the longitudinal (ω_LO) and transverse (ω_TO) frequencies of the long-wavelength T_1u modes are determined by the Kramers-Kronig transformation of the reflectance spectra. The experimental data are compared and discussed with the theoretical results obtained by the rigid ion model. Our theoretical analysis reveals that the bonds in the tetrahedra exhibit a covalent character while those in the dodecahedra almost ionic character, which is in accordance with the results for other materials of this crystal family.     

Photoelectric Properties of the In/CuIn3Se5 and In/CuGa3Se5 Structures

Using the method of oriented crystallization of a melt (a vertical variant), we grew homogeneous single crystals of the ternary compounds CuIn₃Se₅ and CuGa₃Se₅. Photosensitive structures based on them were created for the first time, the spectral dependences of the relative quantum efficiency of the phototransformation of structures were investigated, and the energy gap width of the ternary compounds was determined. It is established that the CuIn₃Se₅ and CuGa₃Se₅ compounds are materials with direct interband transitions. We show that the structures created can be used as wideband photoconverters of natural radiation.     

Hyperfine Interactions in Tb3In5

The static quadrupole interaction at the In site of the rare earth intermetallic compound Tb₃In₅ has been studied at room temperature by TDPAC technique. The results were compared with some Point Charge Model calculations, using 2 or 3 for the In charge, suggesting the value 3. Some additional AC susceptibility measurements indicated that this sample may be antiferromagnetic. This revised version was published online in September 2006 with corrections to the Cover Date.     

5f electron localization-delocalization transition from UPd3 to UPt3

The electronic structures of URh (3), UPd (3), UPt (3), and UAu (3) are calculated with the self-interaction corrected local-spin-density approximation. We find that only in URh (3) the f electrons are fully delocalized. UPt (3) has one f electron localized at each U site, while a localized f(2) configuration of the U ion is found for UPd (3). It is predicted that, upon application of a pressure of 25 GPa, UPd (3) will acquire the f(1) configuration and possibly exhibit heavy-fermion behavior. We find that UAu (3) is characterized by the same mixed localized-delocalized f-electron manifold as UPd (3).     

Enhanced superhyperfine interaction on Ru3+ in Tm3Al5O12 and on Ru3+ and Yb3+ in Tm3Ga5O12

Measurements of the enhanced superhyperfine interaction linking the electron spin of an impurity EPR ion and the nuclear moments of Van Vleck host lattice ions are reported for Ru³⁺ in Tm₃Al₅O₁₂ and for Ru³⁺ and Yb³⁺ in Tm₃Ga₅O₁₂. The Ru³⁺ results appear to be the first reported where this interaction is large enough to give rise to a well resolved superhyperfine structure. For Yb³⁺ the observed temperature dependent line narrowing evidences the role of Tm spin fluctuations.     

Contribution to ε′/ε from anomalous gauge couplings

Recently the KTev Collaboration has measured Re (ε′/ε)=(28±4.1)×10⁻⁴ which is in agreement with early measurements from NA31. The Standard Model prediction for ε′/ε is on the lower end of the experimentally allowed range depending on models for hadronic matrix elements. In this paper we study the contributions from anomalous gauge couplings. We find that the contributions from anomalous couplings can be significant and can enhance ε′/ε to have a value closer to data.     

3-萘基-5-萘偶氮基-[1,3,4]-噻二唑-2-硫酮的合成及谱学研究

3-萘基-5-萘偶氮基-[1,3,4]-噻二唑-2-硫酮由二-α-萘基硫代卡巴腙与二硫化碳在碱性条件下发生加成闭环反应生成.文章研究了该反应的历程,提出该反应的机理是亲核加成,并通过IR谱、UV谱和NMR谱对标题化合物的结构进行了表征.     

The nature of activation centers in Y2SiO5:Pr3+, Gd2SiO5:Pr3+, and Lu2SiO5:Pr3+ crystals

A complex study of the energy spectra and relaxation channels for the excitation energy of activation centers in Y₂SiO₅:Pr³⁺, Lu₂SiO₅:Pr³⁺, and Gd₂SiO₅:Pr³⁺ was performed. An analysis of the low-temperature optical spectra showed that the energy parameters and the character of field splitting of the ¹ D ₂ and ³ H ₄ activator ion terms were substantially different in crystals of different crystallographic types. The pseudosymmetry effect was observed in splitting of the ¹ D ₂ and ³ H ₄ terms of Pr³⁺ ions situated in nonequivalent crystal lattice cation sites of Y₂SiO₅ and Lu₂SiO₅. Activator ions nonuniformly populated nonequivalent cation sites of the Y₂SiO₅ crystal lattice. At high activator ion concentrations (>1 at %), luminescence decay in Y₂SiO₅ could not be described by a simple exponential time dependence. The complex luminescence decay law was caused by activator ion excitation energy migration and capture by acceptors. The role of energy acceptors was played by activator ion dimers.     

Magnetic-field-controlled polarized luminescence of Y3Al5O12-Tb and Y3Al5O12-Ho garnets

The circularly polarized luminescence spectra of Y₃Al₅O₁₂-Tb and Y₃Al₅O₁₂-Ho garnets are analyzed in the wavelength ranges of the ⁵ D ₄ → ⁷ F ₅ transition in the Tb³⁺ ion and the ⁵ S ₂ → ⁵ I ₈ transition in the Ho³⁺ ion. It is found that the intensities of the orthogonal circularly polarized components of the series of luminescence lines attributed to the studied garnets differ substantially. The results obtained are interpreted in terms of the mixing of the Tb³⁺ and Ho³⁺ electronic states in an external magnetic field.     

Conical spiral in Tb5Sb3 compound

Neutron diffraction measurements performed on the Tb₅Sb₃ compound, which crystallizes in the hexagonal Mn₅Sb₃-type structure, indicate that the magnetic structure of the compound is a conical spiral between 150 and 80 K with a propagation vector k = [0,0,0.1414] and terbium magnetic moments 5.8 and 3.5 μ_B for the two sites, respectively. The axis of the cone makes an anlge of 51.5° with the c-axis of the crystal at 100 K. The anlge between the axis of the cone and the direction of the moments of both sites is found to be 28.5°. Below 80 K the diagram becomes very complicated with many peaks at low angles with more than one propagation vector.     

Photosensitive n-Ox/p-CuIn3Se5 heterostructures

We have created photosensitive heterostructures n-Ox/p-CuIn₃Se₅ for the first time. The synthesis process is based on thermal reaction of the ternary compound with atmospheric oxygen. We have studied the voltage-current characteristics and the photoconversion quantum efficiency spectra of the indicated structures. We discuss charge transport mechanisms and photosensitivity of the created structures. We show that n-Ox/p-CuIn₃Se₅ heterostructures can be used in designing solar cells and photoanalyzers for linearly polarized radiation. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 6, pp. 782–785, November–December, 2006.