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Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24 GPa

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3., YUN Jinku 1 , SUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. Key Laboratory of Metastable Materials Science and technology, Yanshan University, Qinhuangdao 066004, china 2. center for {3. matter physics, Institute of physics, Chinese Academy of Sciences, Beijing 100080, china 3. BSRF, Institute of High Energy physics, Chinese Academy of Sciences, Beijing 10003., china Key Laboratory of Metastable Materials Science and technology Yanshan University Qinhuangdao China center for condensed matter {3. Institute of Physics Chinese Academy of Sciences Beijing China BSRF Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24 GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science china Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2, WANG Jin3. WU Yishi1, YUAN Gu3. AI Xicheng1, WANG Li4 & ZHANG Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, china 2. School of Life Science and technology, Beijing Institute of technology, Beijing 100081, china 3. College of Chemistry and Molecular Engineering, Peking University, Beijing 100080, china 4. center for condensed matter physics, Institute of physics, Chinese Academy of Sciences, Beijing 100080, china Correspondence should be addressed to Ai Xicheng and Zhang Jianping State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China School of Life Science and technology Beijing Institute of Technology Beijing China College of Chemistry and Molecular Engineering Peking University Beijing China center for condensed matter {3. Institute of Physics Chinese Academy of Sciences Beijing China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 3. ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

An Explicit Function Expression for dc Bias and Temperature Dependence of Magnetoresistances in Magnetic Tunnel Junctions

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Journal of Materials Science & technology 2002年第6期18卷 497-501页

作者： Xiufeng HANState Key Laboratory of Magnetism, Institute of physics and center of condensed {3. physics, Chinese Academy of Sciences, Beijing 100080, china Chinese Acad Sci Inst Phys State Key Lab Magnetism Beijing 100080 Peoples R China Chinese Acad Sci Ctr Condensed Matter Phys Beijing 100080 Peoples R China

An explicit function expression for the bias voltage or/and temperature dependences of tunnel magnetoresistance ratio and resistances were obtained with a unique set of intrinsic parameters. Two of these intrinsic parameters are the Curie temperature TC and the density of state (DOS) for itinerant majority and minority electrons ξ(ρM/ρm), which are the eigen parameters of ferromagnetic electrodes. Others are the spin-dependent matrix-element ratio (i.e., |Td|2/|TJ|2 ) and the anisotropic-wavelength-cutoff energy ECγ of spin-wave spectrum in magnetic tunnel junction (MTJ), which are the structure parameters of an MTJ. These intrinsic parameters can be predetermined using the experimental measurement or, in principle, using the first-principle calculation method for an MTJ with the three key layers of FM/I/FM. Furthermore, a series of experimental data for an MTJ, for example, a spin-valve-type MTJ of Ta (5 nm)/Ni79Fe21(25 nm)/lr22Mn78(12.nm)/Co75Fe25(4 nm)/AI(0.8 nm)-oxide/Co75Fe25(4 nm)/Ni79Fe21(20 nm)/Ta (5 nm) in this work, can be self-consistently evaluated and explained using such concise explicit function formulations.

关键词： Magnetic tunnel junction TMR Spin-electron transport Magnon excitation Spin-polarization Magnetotransport

Mechanisms of the pancake vortex and vortex line movement in the high T_c superconductors Bi_2Sr_2CaCu_2O_8+δ and La_(1.93.Sr0.0_7CuO_4+δ

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Science china(physics,Mechanics & Astronomy) 2007年第2期50卷 240-248页

作者： WANG WeiXian1,ZHOU Fang2,TAN Shun1,WU Huan1 & ZHANG YuHeng1 1 National High Magnetic Field Laboratory,University of Science and technology of china,Hefei 23.026,china 2 National Laboratory for Superconductivity,lnstitute of {3. and the center for condensed matter {3.,Chinese Academy of Sciences,Beijing 100080,china National High Magnetic Field Laboratory University of Science and Technology of China Hefei China National Laboratory for Superconductivity Institute of Physics and the Center for Condensed Matter Physics Chinese Academy of Sciences Beijing China

In the strict sense, it is not very clear why with magnetic field increasing, the normal-superconductive (NS) transition becomes broad for Bi2Sr2CaCu208+δ(Bi2212. while the NS transitions are almost parallel for La193.roo7Cu04+δ(La214). In this paper, R-T relations are measured by the six-probe method. We propose a moving mechanism of the pancake vortex and vortex line for Bi2212. The theoretical curves fit the experiment data well.

关键词： superconductivity superconductive pancake vortex dynamics

Pressure-induced crystallite breaking in La_(0.7)Sr_(0.3.Mn_(0.9)Fe_(0.1)O_3.nanosolids

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Chinese Science Bulletin 1998年第6期43卷 458-461页

作者： ZHENG Fanlei 1, 2, SUI Yu 1, 3. XU Dapeng 1 and SU Wenhui 1, 4 1. Department of physics, Jilin University, Changchun 13.023. china 2. Changchun Institute of physics, Chinese Academy of Sciences, Changchun 13.021, china 3. Institute of Metal R Department of physics Jilin University Changchun Chinas Changchun Institute of physics Chinese Academy of Sciences Changchun China Institute of Metal Research Chinese Academy of Sciences Shenyang China International center for Materials physics Chinese Academy of Sceinces Shenyang China center for condensed matter and {3. physics CCAST (World Lab.) Beijing China

In the compacting process of the La 0.7Sr 0.3.n 0.9Fe 0.1O 3.nanosolids under the pressure range of 0.0-4.5 GPa, the apparent pressure-induced crystallite breaking phenomenon in these nanosolids was observed. With increasing pressure up to 4.5 GPa, the average grain size decreases by 46% while the magnetization of nanosolids decrease by 40% and their coercive increases by 3.%. This kind of breaking has a close relation to the existence of oxygen deficiency in La 0.7Sr 0.3.n 0.9Fe 0.1O 3.nanoparticles. A simple and convenient method for preparing the bulk nanosolids with a large number of clean interfaces has been suggested.

关键词： nanosolid pressure-induced breaking high pressure.

Studies of Structure Evolution of Nanostructured Hf_(11)Ni_(89) Alloy

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Journal of Materials Science & technology 1998年第3期14卷 205-210页

作者： Zhenfu DONG and Lianmao PENG(Beijing Lab. of Electron Microscopy, Institute of physics and center for condensed {3. physics,Chinese Academy of Sciences, P.O.Box 2724, Beijing 100080, china)Ke LU and Zhuangqi HU(State Key Lab. for RSA, Institute of Meta Beijing Lab. of Electron Microscopy Institute of Physics and Center for Condensed Matter Physics Chinese Academy of Sciences P.O.Box 2724 Beijing 100080 China State Key Lab. for RSA Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

A nanostructured Hf11Ni89 ribbon sample was prepared by melt-spinning. It was found that the as-quenched sample is composed of a major HfNi5 compound nanophase and an interfacial magnetic Ni(Hf) solid solution phase. The structure evolution of the sample was studied by using X-ray difFraction (XRD), transmission electron microscopy (TEM), difFerential scanning calorimetry (DSC), resistivity and magnetothermal analysis. Upon heating, a second precipitation process of the Ni(Hf) phase prior to grain growth wa5 detected by means of both structural analysis and physical property measurements. The measurement results are discussed based on the relationship between microstructure and physical properties.

关键词： Studies of Structure Evolution of Nanostructured Hf Alloy Ni

A new way of transformation from a-quartz to coesite

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Progress in Natural Science:Materials International 2006年第10期16卷 1090-1097页

作者： SU Wenhui, LIU Shue, XU Dapeng, WANG Weiran, YAO Bin, GUO Xingyuan, LIU Zhiguo, and ZHONG Zheng ( center for the condensed matter Science and {3., Harbin Institute of {3., Harbin 150001, china center for Rare-Earth Solid State physics, Jilin University, Changchun 13.023. china International center for Materials physics, Chinese A-cademy of Sciences, Shenyang 110015, china center for condensed matter and radiation physics, china center of Advanced Science and {3. (World Laboratory), Beijing 100080, china Department of physics, University of Windsor, Windsor, ON N9B 3.4, Canada) center for Rare-Earth Solid State physics Jilin University Changchun 130023 China International center for Materials physics Chinese Academy of Sciences Shenyang 110015 China center for condensed matter and {3. physics China Center of Advanced Science and Technology (World Laboratory) Beijing 100080 China center for the condensed matter Science and {3. Harbin Institute of Technology Harbin 150001 China Department of physics University of Windsor Windsor ON N9B 3P4 Canada

A laboratory method combining the high-energy mechanical ball milling and high static pressure has been suggested for modelling synthesis of coesite in the Earth's crust. A window of milling time, a mechanical collision-induced intermediate phase ofα-quartz and its condition of easily crystallizing into coesite under the condition of 3.0 GPa, 923.K, < 1.0 min have been discovered. The new method needs much shorter synthesizing time and lower synthesizing critical pressure than those used before. The Raman spectra for the coesite synthesized by the present method have covered all the information of those natural and synthesized coesites reported before. It is demonstrated that this method has a great potential in geo-science research and implied the other possible mechanism of coesite formation in the Earth's crust.

关键词： quartz-coesite high-energy mechanical ball milling high state pressure Raman spectrum metastable phase sub-duction-exhumation of plate.

Coherent coupling of vibrational states in the MEH-PPV film investigated through Multi-Color Photon Echo

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Science china(physics,Mechanics & Astronomy) 2010年第6期53卷 1020-1023页

作者： YU GuoYang 1 ,SONG YunFei 1 ,WANG YingHui 1 ,LIU YuQiang 1 ,MO YueQi 2 & YANG YanQiang 1 1 center for condensed matter Science and {3.,Department of physics,Harbin Institute of {3.,Harbin 150001,china 2 College of Materials Science and Engineering,South china University of {3.,Guangzhou 510640,china center for condensed matter Science and {3. Department of Physics Harbin Institute of Technology Harbin China College of Materials Science and Engineering South China University of Technology Guangzhou China

The poly-[2-methoxy,(5-2′-ethyl-hexyloxy)-p-phenylene vinylene](MEH-PPV) film is investigated by means of the Multi-Color Photon Echo(MCPE) technique. Under the three-order nonlinear response theory,the reason for the occurrence of the quantum beats in the time domain and the relations among signal wavevector,pulse sequence and response function are discussed. The analysis of the Raman spectrum of MEH-PPV and the fast Fourier transformation(FFT) results of photon echo(PE) signal dynamics demonstrate the coherent coupling between the C==C bonds and the CC-H bonds and the coherent coupling between the C-C stretching of the phenyl group and the C==C stretching of the vinylene group.

关键词： MCPE quantum beats coherent coupling

Spin-glass like behaviors in La_(1-x)Tb_xMnO_3.perovskite

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Science china(physics,Mechanics & Astronomy) 2009年第12期52卷 1893-1897页

作者： ZHANG YingTang1,2,3.WANG ChunChang2,4,LIU WeiBin1,WANG Zhong3.LU HuiBin2 & CHEN ZiYu1 1 Department of physics,Beijing University of Aeronautics and Astronautics,Beijing 100191 2 Institute of physics & center for {3. matter physics,Chinese Academy of Sciences,Beijing 100190 3.School of Material Science & Engineering,Shaanxi University of technology,Hanzhong 723.03.4 Institute of Superconducting and Electronic Materials,Wollongong University,Northfield Ave,Gwynneville,NSW 2522,Australia Department of physics Beijing University of Aeronautics and Astronautics Beijing China Institute of physics & center for condensed {3. physics Chinese Academy of Sciences Beijing China School of Material Science & Engineering Shaanxi University of Technology Hanzhong China Institute of Superconducting and Electronic Materials Wollongong University Gwynneville Australia

A series of samples of La1-xTbxMnO3.(0≤x≤0.15) are prepared. The static and dynamic magnetizations of La1-xTbxMnO3.have been investigated. The results indicate that the spins with the short-range order are frozen into random direction at low enough temperatures which leads to the samples exhibiting the spin-glass like behavior. It is considered that the spin-glass like behavior originates from the competition between ferromagnetic double exchange among Mn3. and Mn2+ and antiferromagnetic superex-change among Mn3. and Mn3.,as well as Tb3. and Tb3..

关键词： La1-xTbxMnO3 spin-glass-like behavior short-range order