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Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(2..5) bulk metallic glass up to 2. 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 Condensed {2. {2., Institute of {2., chinese academy of sciences, beijing 100080, China 3. BSRF, Institute of High Energy {2., chinese academy of sciences, beijing 10003., China Key laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao China Center for Condensed matter physics 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 Zr41Ti14Cu12.5Ni10Be2..5 bulk metallic glass (BMG) is investigated at room temperature up to 2. 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.

Research progress in the inner surface modification of metal tubes by plasma processing

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Progress in Natural Science:Materials International 2006年第11期16卷 1119-1126页

作者： ZHANG Guling~ 1,2.**, WU Xingfang~1, GU Weichao~2. CHEN Guangliang~2. FENG Wenran~2. NIU Erwu~2. LI Li~2. L Guohua~2. CHEN Huan~2. FAN Songhua~2. LIU Chizi~2.and YANG Size~2.1. School of Material Science and Engineering, University of Science and Technology beijing, beijing 10008{2. China 2. beijing {{2. laboratory for Condensed matter physics, Institute of physics, chinese academy of sciences, beijing 100080, China) School of Material Science and Engineering University of Science and Technology Beijing Beijing 100083 China beijing national {2. for Condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The recent progress in inner surface hardening of tubes by plasma processing is summerized. Several techniques of inner surface plasma source ion implantation and deposition are introduced, and their advantages and disadvantages are discussed. The basic principles, technical features and new progress of inner surface plasma source ion implantation methods for metal tubes, which were developed in our laboratory, are described in detail. And perspectives of the future technical development for inner surface ion implantation of tubes are presented.

关键词： PSII metal tubes inner surface surface modification.

The size effect on transport properties of colossal magnetoresistance materials La_(0.67)Ca_(0.3.)MnO_3

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Science China(physics,Mechanics & Astronomy) 2008年第3期51卷 251-257页

作者： LI PeiGang1,2.LEI Ming1,2.GUO YanFeng2.GUO Xi2.CHEN LeiMing2. TANG WeiHua1,2.SONG PengYun3.& CHEN JinPing3.1 Department of {2.,Center for Optoelectronics Materials and Devices,Zhejiang Sci-Tech University,Hangzhou 3.0018,China 2.national {2. for Condensed {3. {2.,Institute of {2.,chinese academy of sciences,beijing 100080,China 3.Department of {2.,Peking University,beijing 100875,China Department of physics Center for Optoelectronics Materials and Devices Zhejiang Sci-Tech University Hangzhou China national laboratory for Condensed {2. {3. Institute of Physics Chinese Academy of Sciences Beijing China Department of physics Peking University Beijing China

High quality La0.67Ca0.3.MnO3.(LCMO) film was deposited via a novel pulsed electron deposition technique on SrTiO3.100) single crystal substrate. The micro-bridge with different widths was fabricated by using electron beam lithography (EBL) technique and their transport properties were studied. For the micro-bridges with width of 2.and 1.5 μm,the insulator-to-metal transition temperature (TP) keeps un-changed compared with the film. For the micro-bridges with width of 1 μm,the TP shifts towards the lower temperature by 50 K. When the width decreases down to 500 nm,the insulator-to-metal transition disappears. The magnetoresistance be-havior of these micro-bridges was studied,and the results show that the low field magnetoresistance (LFMR) decreases and the high field magnetoresistances (HFMR) keep almost unchanged as the width of micro-bridge is reduced.

关键词： colossal magnetoresistance pulsed electron deposition electron beam lithography electrical transport properties

Anomalous Hall effect in perpendicular CoFeB thin films

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chinese physics B 2014年第4期23卷 9-17页

作者：朱涛 Institute of physics and beijing {2. {3. for Condensed matter physics Chinese Academy of Sciences

Our recent research achievements in the perpendicular magnetic anisotropy （PMA） properties of the CoFeB sand- wiched by MgO and tantalum layers are summarized. We found that the PMA behaviors of Ta/CoFeB/MgO and MgO/CoFeB/Ta thin films are different. The larger PMA in the latter film is related to the lower magnetization of CoFeB deposited on MgO. Furthermore, we have demonstrated a large anomalous Hall effect in perpendicular CoFeB thin fihn. Our results show large anomalous Hall resistivity, large longitudinal resistivity, and low switching field can be achieved, all at the same time, in the perpendicular CoFeB thin film. Anomalous Hall effect with high and linear sensitivity is also found in an MgO/CoFeBFFa thin film with a thick MgO layer, which opens a door tbr future device applications of perpendicular ferromagnetic thin films.

关键词： anomalous Hall effect perpendicular magnetic anisotropy magnetic properties of interfaces

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

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Science China(physics,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3. REN Hongtao3. JIAO Yulei3.& ZHENG Minghui3.1. Department of physics, College of Science, beijing Jiaotong University, beijing 100044, China 2. {3. of Optical physics, Institute of physics and Center for Condensed matter physics, {12., beijing 100080, China 3. General Research Institute for Nonferrous Metals, beijing 100088, China Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) Department of physics College of Science Beijing Jiaotong University Beijing China laboratory of Optical physics Institute of physics and Center for Condensed {3. physics Chinese Academy of Sciences Beijing China General Research Institute for Nonferrous Metals Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3.7–5 (Y12.0} powder,J c for the superconducting thick film by approaches described above reaches 7.008×103.A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Oxygen pressure dependent electro-resistance in La_(0.9)Sr_(0.1)MnO_3.thin films grown by laser molecular beam epitaxy

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Science China(physics,Mechanics & Astronomy) 2008年第3期51卷 232-236页

作者： OUYANG SiHua1,2.WANG ChunChang2.LIU GuoZhen2.HE Meng2. JIN KuiJuan2.DANG ZhiMin1 & L HuiBin2. College of Materials Science and Engineering,beijing University of Chemical Technology,beijing 10002.,China 2.beijing {3. laboratory for Condensed matter physics,Institute of physics,chinese academy of sciences,beijing 100080,China College of Materials Science and Engineering Beijing University of Chemical Technology Beijing China beijing national {2. for Condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing China

We report here studies on the influence of oxygen pressure on the electroresis-tance behavior of La0.9Sr0.1MnO3.thin films fabricated by laser molecular beam epi-taxy. It was found that the film deposited at lower oxygen pressure shows larger c-axis parameter,higher resistance,and more distinct electroresistance. These results reveal that the electroresistance of manganite thin films can be tuned by the conditions of film fabrication.

关键词： La0.9Sr0.1MnO3 thin film electroresistance effect laser molecular beam epitaxy

Pairwise entanglement and local polarization of Heisenberg model

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Science China(physics,Mechanics & Astronomy) 2008年第10期51卷 1515-1522页

作者： XI XiaoQiang1,2. ZHANG Tao3. YUE RuiHong3.4 & LIU WuMing2.1 Department of Applied Mathematics and {2., Xi’an Institute of Post and Telecommunications, Xi’an 710061, China 2.beijing {2. {3. for Condensed matter {2., Institute of {2., chinese academy of sciences, beijing 100080, China 3.Institute of Modern {2., Northwest University, Xi’an 710069, China 4 Department of {2., Ningbo University, Ningbo 3.52.1, China Department of Applied Mathematics and physics Xi’an Institute of Post and Telecommunications Xi’an China beijing national {2. for Condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing China Institute of Modern physics Northwest University Xi’an China Department of physics Ningbo University Ningbo China

The characteristics of pairwise entanglement and local polarization (LP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2.for odd qubit); LP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the LP, the smaller the probability, and the same LP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3.12.(for odd-qubit chain) or 0.3.91 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

Single-molecule studies of DNA by molecular combing

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Progress in Natural Science:Materials International 2007年第5期17卷 493-499页

作者： Liu Yuying, Wang Pengye and Dou Shuoxing (College of Science, China Agricultural University, beijing 100083. China {2. of Soft {2. {3., beijing national {2. for Condensed {2. {3., Institute of {3., chinese academy of sciences, {12., China) College of sciences China Agricultural University Beijing 100083 China laboratory of Soft matter {2. Institute of Physics Chinese Academy of Sciences Beijing 100080 China beijing national {2. for Condensed {3. physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

Molecular combing is a powerful method for aligning a large array of DMA molecules onto a surface. It is a process whereby DNA molecules are stretched and aligned on a glass surface by the force via fluid flow. The ability to comb up to several hundred DNAs on a single cover slip allows for a statistically significant number of measurements to be made. These features make molecular combing an attractive tool for genomic studies, such as DNA replication, DNA transcription, DNA-protein interaction and so on. In this review article, we discuss the molecular combing principle, method and its applications.

关键词： DNA molecule molecular combing DNA-protein interaction.

Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

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Science China(physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3. WANG Yong2. DU Xiaolong1, MEI Zengxia1, KONG Xianghe3. JIA Jinfeng1, XUE Qikun1 & ZHANG Ze2. 4 1. State Key {2. for Surface physics, Institute of physics, {3., beijing 100080, China 2. {2. of Electron Microscopy, Institute of physics, {3., beijing 100080, China 3. College of physics and Engineering, Qufu Normal University, Qufu 2.3.65, China 4. beijing University of Technology, beijing 10002., China State Key laboratory for Surface physics Institute of Physics Chinese Academy of Sciences Beijing China College of physics and Engineering Qufu Normal University Qufu China laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing China beijing University of Technology Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 3. rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.