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An Y.,Key Laboratory of Display Materials and Photoelectric Devices | An Y.,Tianjin University of Technology | Duan L.,Key Laboratory of Display Materials and Photoelectric Devices | Duan L.,Tianjin University of Technology | And 4 more authors.
Applied Surface Science | Year: 2011

[Co(30 )/Pt(x )]20 multilayers with the Pt layer thicknesses varying from 5 to 20 were characterized structurally by high angle X-ray diffraction, X-ray reflectivity, X-ray absorption spectroscopy and magnetically by X-ray magnetic circular dichroism. It is found that the structure and magnetic properties of Pt have a strong correlation with the Pt layer thickness. The 20 thickness Pt layer is not almost influenced by the adjacent Co layer and the nearest neighbors are dominated by Pt-Pt shells. With decreasing Pt layer thickness, the nearest neighbors are gradually dominated by Pt-Co shells and the Pt-Co intermixing regions also remarkable increase at the interfaces, especially for the 5 thickness Pt layer. The orbital and spin magnetic moments as well as the ratio morb/mspin all decrease systematically with increasing Pt layer thickness, indicating that the interface atoms are polarized by direct Pt-Co hybridization, but that the adjacent layers are polarized by Pt-Pt interactions. © 2011 Elsevier B.V. All rights reserved.


Qin W.-J.,Tianjin University of Technology | Dai C.-J.,Tianjin University of Technology | Dai C.-J.,Key Laboratory of Display Materials and Photoelectric Devices | Xiao Y.,Tianjin University of Technology
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2010

In this work, 4f66pnl and 4f55d6snl (l=0,2) autoionizing states of the samarium (Sm) atom, especially those with lower principal quantum number, have been studied, using the isolated-core excitation scheme with three dye lasers. In the energy region between 57 990 and 61 030 cm-1, there are 74 autoionizing states of the Sm atom observed. These states can be classified into the autoionization series converging to four different ionization limits. In most cases, the line shapes of these autoionizing states are nearly symmetric, from which the level energies and widths can be easily obtained by fitting the experimental spectra to the Lorentzian profiles. In addition, several spectroscopic properties of these autoionizing states, such as configuration interaction, are also discussed. © 2009 Elsevier Ltd. All rights reserved.


Qin W.J.,Tianjin University of Technology | Dai C.J.,Tianjin University of Technology | Dai C.J.,Key Laboratory of Display Materials and Photoelectric Devices | Xiao Y.,Tianjin University of Technology
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2010

The investigation of the samarium (Sm) atom autoionizing states, belonging to the 4f 6 6pnl and 4f 5 5d6snl (l=0, 2) configurations, has been carried out by using a three-step isolated-core-excitation (ICE) scheme. Fifty-seven new autoionizing states of the Sm atom have been observed in the energy region between 60,700 and 66,500 cm -1. These autoionizing states are classified into five autoionization series in the light of different ionization limits. In most cases, the transition profiles of these autoionizing states are nearly symmetric, from which the peak positions and widths can be easily obtained by Lorentzian-profile-fitting procedure. Some autoionizing states have multi-peak profiles whose spectroscopic properties are analyzed in order to understand the complicated structures. © 2010 Elsevier Ltd. All rights reserved.


Wang M.,Key Laboratory of Display Materials and Photoelectric Devices | Xie F.,Tianjin University of Technology | Li W.,Key Laboratory of Display Materials and Photoelectric Devices | Chen M.,Key Laboratory of Display Materials and Photoelectric Devices | Zhao Y.,University of Wollongong
Journal of Materials Chemistry A | Year: 2013

Various kinds of copper sulfides (CuS, a mixture of Cu7S 4-CuS and Cu9S5) were synthesized by simply adjusting the amount of copper chloride and sodium sulfide in a solvothermal process. The different molar ratios of copper chloride and sodium sulfide result in the formation of different kinds of copper sulfides with various morphologies, such as tiny particle, hexagonal plate and octahedron. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. And the optical properties of the products were recorded by means of UV-Vis absorption and photoluminescence spectroscopy. Moreover, due to the presence of visible light, we found that the catalytic activities of the products for oxidation and decomposition of Rhodamine B with the assistance of hydrogen peroxide were enhanced, and the degradation efficiency of RhB was increased from 40% to 98% in 15 minutes at room temperature. © 2013 The Royal Society of Chemistry.


Li M.,Tianjin University of Technology | Dai C.-J.,Tianjin University of Technology | Dai C.-J.,Key Laboratory of Display Materials and Photoelectric Devices | Xie J.,Tianjin University of Technology
Journal of Quantitative Spectroscopy and Radiative Transfer | Year: 2011

Two-color stepwise excitation and photoionization schemes are adopted to study the spectra of bound even-parity high-lying states of the Sm atom with three different excitation paths via the 4f66s6p 7DJ (J=1, 2 and 3) intermediate states. In order to obtain the information of these high-lying states, the Sm atom in these high-lying states is photoionized with an extra photon. Among 231 states detected in the energy region between 35,545 and 44,225cm-1, 108 states are newly discovered, while the rest can be identified as the same with the literature. In most cases, comparisons of the spectra corresponding to the three different excitation paths may partially determine the total angular momentum of the observed peaks with the selection rules. In addition, the relative intensities of all related transition lines are given. © 2010.


Jing H.,Key Laboratory of Display Materials and Photoelectric Devices | Jing H.,Tianjin University of Technology | Ye S.-W.,Key Laboratory of Display Materials and Photoelectric Devices | Ye S.-W.,Tianjin University of Technology | And 2 more authors.
Chinese Physics B | Year: 2015

The radiative lifetimes of the Eu 4f76snp (8PJ or 10 PJ) Rydberg states with J = 5/2 and 11/2 are investigated with a combination of multi-step laser excitation and pulsed electric field ionization, from which their dependence on the effective principal quantum number is observed. The lifetimes of 21 states are reported along with an evaluation of their experimental uncertainty. The influence of blackbody radiation, due to the oven temperature, on the lifetime of the higher-n states is detected. The non-hydrogen behavior of the investigated states is also observed. © 2015 Chinese Physical Society and IOP Publishing Ltd.


Liang H.-R.,Tianjin University of Technology | Liang H.-R.,Key Laboratory of Display Materials and Photoelectric Devices | Shen L.,Tianjin University of Technology | Shen L.,Key Laboratory of Display Materials and Photoelectric Devices | And 4 more authors.
Wuli Xuebao/Acta Physica Sinica | Year: 2014

A velocity-map-imaging (VMI) method is employed to investigate systematically the dynamical process of ejected electrons from autoionizing states of the Eu atom for the first time as far as we know. An atom is excited stepwise from the 4f76s6s8S7/2 ground state to the 4f76s8s8P7/2 Rydberg state via the 4f76s6p6P5/2 intermediate state, then further excited to the 4f76p1/2 (J = 3)8s and 4f76p1/2 (J = 4)8s autoionizing states using the three-step isolated-core excitation method. According to the excitation pathways and selection rules, the value of total angular momentum of the autoionizing state can be calculated. The energy conservation and angular momentum parity conservation would enable us to determine the final states during the autoionizing process. The ejected electron, which decays from the autoionizing process, can be focused and imaged by the electron lens and the kinetic energy of it is resolved by the position sensitive detector. By combining velocity-map-imaging method with the mathematical transformation, the ejected electron energy distribution can be obtained, also the branching ratio is confirmed. Simultaneously, by tuning the wavelength of the third laser, the characteristic of the branching ratio following the variation of the photon energy, and the possibility of the population inversion have been discussed. © 2014 Chinese Physical Society.


Zhao Y.-H.,Key Laboratory of Display Materials and Photoelectric Devices | Zhao Y.-H.,Tianjin University of Technology | Dai C.-J.,Key Laboratory of Display Materials and Photoelectric Devices | Dai C.-J.,Tianjin University of Technology | And 2 more authors.
Chinese Physics B | Year: 2013

Spectra of autoionizing states of the Sm atom in an energy region between 45948.9 cm-1 and 46943.6 cm-1 are systematically investigated by a three-color multi-step resonant excitation scheme with three different excitation paths. The three intermediate states, 4f 66s7s 7F3, 4f 66s7s 7F4, and 4f 66s7s 9F5 are employed for the three paths, respectively. Based on precise calibration of wavelength, the level energies of 112 autoionizing states are determined with the line widths and the relative line intensities of the related transitions. The possible influence of configuration interaction on the line shape of autoionizing state is also discussed. In addition, a unique value of J, the total angular momentum, is assigned to all detected states by comparing the three spectra obtained with the different excitation paths. © 2013 Chinese Physical Society and IOP Publishing Ltd.


Ye S.,Key laboratory of Display Materials and Photoelectric Devices | Ye S.,Tianjin University of Technology | Dai C.,Key laboratory of Display Materials and Photoelectric Devices | Dai C.,Tianjin University of Technology | And 2 more authors.
Guangxue Xuebao/Acta Optica Sinica | Year: 2012

The even-parity highly excited states of europium (Eu) atom have been investigated with resonant excitation and electric field ionization (EFI) method. Among the 89 states detected, the information about level energy and spectral assignment of 56 states have not been reported previously. A combination of analysis of their effective principal quantum numbers, quantum defects, and the comparison with literature, enable us to classify them as the 4f 76s ( 9S) np ( 8P J or 10P J) Rydberg series, which fills the gap in previous literature for the n=19-39 states of the series. Besides, the ionization limit of Eu atom is suggested to be at 45734.2 cm -1, near which the existence of a broad pedestal is also explained.


Wang S.,Key Laboratory of Display Materials and Photoelectric Devices | Wang S.,Tianjin Key Laboratory for Photoelectric Materials and Devices | An Y.,Key Laboratory of Display Materials and Photoelectric Devices | An Y.,Tianjin Key Laboratory for Photoelectric Materials and Devices | And 5 more authors.
Journal of Applied Physics | Year: 2013

Cr-doped In2O3 films were deposited on Si (100) substrates by RF-magnetron sputtering technique. The local structure, magnetic, and transport properties of films are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, X-ray absorption fine structure, Hall effect, R-T, and magnetic measurements. Structural analysis clearly indicates that Cr ions substitute for In3 sites of the In2O3 lattice in the valence of 2 states and Cr-related secondary phases or clusters as the source of ferromagnetism is safely ruled out. The films with low Cr concentration show a crossover from semiconducting to metallic transport behavior, whereas only semiconducting behavior is observed in high Cr concentration films. The transport property of all films is governed by Mott variable range hopping behavior, suggesting that the carriers are strongly localized. Magnetic characterizations show that the saturated magnetization of films increases first, and then decreases with Cr doping, while carrier concentration nc decreases monotonically, implying that the ferromagnetism is not directly induced by the mediated carriers. It can be concluded the ferromagnetism of films is intrinsic and originates from electrons bound in defect states associated with oxygen vacancies. © 2013 AIP Publishing LLC.

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