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Dynamics of interchain delocalized polarons in polymers

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Science china(physics,Mechanics & Astronomy) 2010年第12期53卷 315-320页

作者： LIU Wen1,2,GAO Kun1,LI Yuan1,SUN Zhen1 & LIU DeSheng1,2 1 school of physics,shandong university,jinan 250100,china 2 Department of physics,Jining university,Qufu 273155,china school of physics Shandong University Jinan China Department of physics Jining University Qufu China

Polaron dynamics in a system of highly ordered conjugated polymer chains is investigated based on the tight binding model. With the interchain coupling enhancing,it takes longer time for the electron added to the system to induce a localized polaron state. Beyond a certain strength of the interchain coupling,the electron evolves into a two-dimensional delocalized polaron state. Dynamical simulations suggest that the well-ordered organic molecule systems with two-dimensional polarons exhibit higher mobilities than the systems with intrachain localized polarons,as also suggested by earlier experiments.

关键词： polaron interchain coupling mobility

Study progresses of lead-free piezoelectric ceramic

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Study progresses of lead-free piezoelectric ceramic

Effect of Pd doping on the acetone-sensing properties of NdFeO

第七届中国功能材料及其应用学术会议

作者： ZHANG Jia-liang~(1,2) (1.school of physics,shandong university,jinan 250100,china 2.State Key Laboratory of Crystal Materials,shandong university,jinan 250100,china)

Pb(Zr,Ti)O-based piezoelectric ceramics have been popularly utilized in many electronic devices for several ***,there is increasingly strong trend to replace them from the viewpoint of environmental *** presentation will report our study progresses of BaTiO-based and(K,Na)NbO-based lead-free piezoelectric ceramic obtained in the past few years.

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International Journal of Minerals,Metallurgy and Materials 2012年第2期 141-145页

作者： Zhan-lei Wu1), Ru Zhang1), Ma Zhao1), Shao-ming Fang1), Zhou-xiang Han1), Ji-fan Hu2), and Kai-ying Wang3) 1) Henan Provincial Key Laboratory of Surface & Interface, Zhengzhou university of Light Industry, Zhengzhou 450002, china 2) school of physics, shandong university, jinan 250100, china 3) Institute for Microsystem Technology, Vestfold university College, Horten 3184, Norway

The acetone-sensing properties of the undoped and Pd doped perovskite-type oxides NdFeO3 were investigated from room temperature to 400°C. The perovskite-type NdFeO3 was synthesized by a sol-gel method, and the dopants Pd with the content from 1wt% to 5wt% were implanted into NdFeO3 nanoparticles by thermal diffusion. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques show that NdFeO3 is an orthorhombic structure with the average particle size of about 40 nm. A giant acetone-sensing response of 675.7 is observed when the Pd content in NdFeO3 powders is about 3wt%. The response and recovery time of the sensor to the 5×10-4 acetone gas are 16 and 1 s, respectively. At the same time, it performs a good selectivity to acetone gas and may be a new promising material candidate for the acetone-sensor development.

关键词： neodymium compounds nanostructures palladium doping acetone sensors sol-gel process

单量子点在双脉冲激发下偏振光子发射的统计特性

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物理学报 2011年第8期60卷 273-277页

作者：古丽姗王东升彭勇刚郑雨军昌吉学院物理系昌吉831100 山东大学物理学院济南250100

用产生函数(generating function)方法对单个半导体量子点系统在外加双脉冲场作用下发射偏振(x偏振和y偏振)光子的统计性质进行了研究.研究结果表明,量子相干对单量子点系统的吸收线型、Mandel参数Q与x偏振光子和y偏振光子之间的高阶交... 详细信息

用产生函数(generating function)方法对单个半导体量子点系统在外加双脉冲场作用下发射偏振(x偏振和y偏振)光子的统计性质进行了研究.研究结果表明,量子相干对单量子点系统的吸收线型、Mandel参数Q与x偏振光子和y偏振光子之间的高阶交叉关联具有显著的影响.

关键词：量子点三能级体系产生函数双脉冲

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纳米复合永磁材料的有效各向异性与矫顽力

物理学报 2003年第3期52卷 703-707页

作者：高汝伟冯维存王标陈伟韩广兵张鹏刘汉强李卫郭永权李岫梅山东大学物理与微电子学院济南250100 钢铁研究总院功能材料研究所北京100081

研究了纳米Nd2 Fe1 4B α Fe复合永磁材料中晶粒交换耦合相互作用对有效各向异性的影响和变化规律 .结果表明 :晶粒之间的交换耦合作用使材料的有效各向异性Keff随晶粒尺寸的减小而下降、随软磁性相成分的增加而降低 .当晶粒尺寸减小到 ... 详细信息

研究了纳米Nd2 Fe1 4B α Fe复合永磁材料中晶粒交换耦合相互作用对有效各向异性的影响和变化规律 .结果表明 :晶粒之间的交换耦合作用使材料的有效各向异性Keff随晶粒尺寸的减小而下降、随软磁性相成分的增加而降低 .当晶粒尺寸减小到 4nm时 ,Keff值减小为其各自通常各向异性常数值的 1 3— 1 4 .有效各向异性的变化特点与矫顽力的变化规律基本相同 .

关键词：纳米复合永磁材料交换耦合相互作用有效各向异性矫顽力磁性晶粒

Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO_2 Films Deposited by APCVD

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Journal of Materials Science & Technology 1997年第1期13卷 50-56页

作者： Deheng ZHANG(Dept. of physics, shandong university, jinan 250100, china)Honglei MA(Institute of Optoelectronic Materials and Devices, shandong university, jinan 250100, china) Dept. of physics Shandong University Jinan 250100 China Institute of Optoelectronic Materials and Devices Shandong University Jinan 250100 China

Transparent conducting F-doped texture SnO2 films with resistivity as low as 5× 10-4 Ω ·cm,with carrier concentrations between 3.5 × 1020 and 7× 1020 cm-3 and Hall mobilities from 15.7 to 20.1 cm2/(V/s) have been prepared by atmosphere pressure chemical vapour deposition (APCVD). These polycrystalline films possess a variable preferred orientation, the polycrystallite sizes and orientations vary with substrate temperature. The substrate temperature and fluorine flow rate dependence of conductivity, Hall mobility and carrier conentration fOr the resultingfilms have been obtained. The temperature dependence of the mobiity and carrier concentrationhave been measured over a temperature range 16～400 K. A systematically theoretical analysis on scattering mechanisms for the highly conductive SnO2 films has been given. Both theoretical analysis and experimental results indicate that for these degenerate, polycrystalline SnO2 ：F films in the low temperature range (below 100 K), ionized impurity scattering is main scattering mechanism. However, when the temperature is higher than 100 K, the lattice vibration scattering becomes dominant. The grain boundary scattering makes a small contribution to limit the mobility of the films.

关键词： SnO cm Conduction Properties and Scattering Mechanisms in F-doped Textured Transparent Conducting SnO2 Films Deposited by APCVD

DENSITY OF INTEGERS THAT ARE THE SUM OF FOUR CUBES OF PRIMES

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Chinese Annals of Mathematics,Series B 2001年第2期22卷 233-242页

作者： REN XIUMIN school of Economics, shandong university, jinan 250100, china. school of Economics Shandong University Jinan 250100 China

Using the circle method and sieves, the author proves that a positive proportion of positive integers can be represented as the sum of four cubes of primes.

关键词： Waring-Goldbach problem Hardy-Littlewood method Sieve methods

Optical waveguides in LiNbO_3 and stoichiometric LiNbO_3 crystals by proton exchange

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Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1479-1488页

作者： LI ShiLing College of physics and Engineering, Qufu Normal university, Qufu 273165, china school of physics and Microelectronics, shandong university, jinan 250100, china College of physics and Engineering Qufu Normal University Qufu China school of physics and Microelectronics Shandong University Jinan China

The formation of optical planar waveguides in LiNbO3 and stoichiometric LiNbO3 crystals by proton exchange was reported. The prism-coupling method was used to characterize the dark-line spectroscopy at the wavelength of 633 and 1539 nm, re-spectively. The mode optical near-field outputs from proton-exchanged LiNbO3 and SLN waveguides at 633 nm were presented. The mode field from stoichiometric LiNbO3 (SLN) waveguide is lighter and more uniform than that from LiNbO3 waveguide, which means the quality of the waveguide in SLN crystal is better than that of the LiNbO3 waveguide. For proton-exchanged LiNbO3 waveguides, the evo-lution of the refractive index profile with annealing was presented. The disorder profiles of Nb atoms in proton-exchanged LiNbO3 waveguides were obtained by Rutherford backscattering/channeling technique. It is shown that the longer the exchange time, the larger the displacement of Nb atoms.

关键词： optical waveguide proton exchange LiNbO3 crystal stoichiometric LiNbO3 crystal

Electronic Structure of New Superconducting Perovskite MgCNi3

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Journal of Materials Science & Technology 2004年第2期20卷 203-205页

作者： Li CHEN, Hua LI and Liangmo MEIphysics and Microelectronic school, shandong university, jinan 250100, china Department of physics, Linyi Teachers university, shandong 276005, china Phys. and Microelectron. Sch. Shandong Univ. Ji'nan 250100 China Dept. of Phys. Linyi Teachers Univ. Linyi 276005 China

The electronic structures of new superconducting perovskite MgCNi3 and related compounds MgCNi2T (T=Co, Fe, and Cu) have been studied using MS-Xa method. In MgCNi3, the main peak of density of states is located below the Fermi level and dominated by Ni d. From the results of total energy calculations, it was found that the number of Ni valence electron decreases faster for the Fe-doped case than that for the Co-doped case. The valence state of Ni changes from +1.43 in MgCNi2Co to +3.02 in MgCNi2Fe. It was confirmed that Co and Fe dopants in MgCNi3 behave as a source of d-band holes and the suppression of superconductivity occurs faster for the Fe-doped case than that for the Co-doped case. In order to explain the fact that Co and Fe dopants in MgCNi3 behave as a source of d-band holes rather than magnetic scattering centers that quench superconductivity, we have also investigated the effects of electron (Cu) doping on the superconductivity and found that both electron (Cu) doping and hole (Co, Fe) doping quench superconductivity exist. Comparing with the hole (Co) doping, there was no much difference between Cu and Co doping. This suggests that Co and Fe doping do not act as magnetic impurity.

关键词： Electronic structure Superconductivity Density of states