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Interface reactions in film materials

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Journal of university of science and technology beijing 2003年第5期10卷 1-8页

作者： fengwu zhu, Zhonghai Thai, and Guanghua Yu{2. science and engineering School, university of science and technology beijing, beijing 100083, china materials science and {2. School University of Science and Technology Beijing Beijing 100083 China

Interface reaction (IR) is a frequently observed phenomenon in the study ofadvanced thin film materials. It is very important to study the reaction conditions at which IRhappens and then to suppress or make use of it, the necessary conditions, including boththermodynamical and dynamical conditions of IR were discussed in detail. IRs in various systems,including oxide/silicon, oxide/metal, metal/metal, metal/semiconductor andsemiconductor/semiconductor, were reviewed. Methods to suppress and make use of IR were alsointroduced.

关键词： interface reaction spin-valve multilayers gate dielectric

Hot Corrosion of Iron in the Presence of Salt Mixture Deposit Containing NaCl and V_2._5 at 600℃

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Journal of materials science & {2. 1996年第6期12卷 445-451页

作者： Lingchuan LI (Dept. of materials science and {2., Tsinghua university beijing 100084, china)Rizhang zhu (Dept. of Surface science and Corrosion {2., university of science and technology beijing, beijing 100083, china)(To whom correspondenc Dept. of materials science and {2. Tsinghua University Beijing 100084 China Dept. of Surface science and Corrosion engineering University of Science and Technology Beijing Beijing 100083 China Instiuto di Chimica Facolta di Ingegneria Università di Genova Fiera del Mare Pad.D 16129 Genova Italy

Iron suffered low temperature hot corrosion (LTHC) in the presence of salt deposits of Na2.O4,Na2.O4 mixed with NaCl and Na2.O4 mixed with V2.5 in a combustion gas at 600℃. The additions of NaCl to Na2.O4 and of V2.5 to Na2.O4 changed the corrosion kinetics significantly and modified the scale structure markedly It is proposed that trivalent iron ions were more favored than divalent ions in the eutectic responsible for the occurrence of LTHC when NaCl was present, while the reaction between Na2.O4 mixed with V2.5 and the gas formed (Na2.)xV2.4(V2.5)6-x providing directly the liquid required by LTHC. The suphide formation in the inner FeO larer was related to the sites of the reduction step wher SO2.was released.

关键词： SO NaCl

The influence of thermal radiation on MHD station-point flow past a stretching sheet with heat generation

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Acta Mechanica Sinica 2011年第4期27卷 502-509页

作者： Jing zhu.Lian-Cun Zheng.Xin-Xin Zhang Department of Mathematics and Mechanics,university of {2. and technology beijing,100083 beijing,china Thermal engineering Department,university of {2. and technology beijing,100083 beijing,china Zheng Department of Mathematics and Mechanics University of Science and Technology Beijing Beijing China Thermal engineering Department University of Science and Technology Beijing Beijing China

This letter is concerned with the plane and axisymmetric stagnation-point flows and heat transfer of an electrically-conducting fluid past a stretching sheet in the presence of the thermal radiation and heat generation or absorption. The analytical solutions for the velocity distribution and dimensionless temperature profiles are obtained for the various values of the ratio of free stream velocity and stretching velocity, heat source parameter, Prandtl number, thermal radiation parameter, the suction and injection velocity parameter and magnetic parameter and dimensionality index in the series form with the help of homotopy analysis method （HAM）. Convergence of the series is explicitly dis- cussed. In addition, shear stress and heat flux at the surface are calculated.

关键词： Thermal radiation MHD Laminar boundarylayers - Homotopy analysis method

Sticking-up Behaviors and Surface Friction of IF Electrogalvanized Sheet Steel in Forming

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International Journal of Minerals,Metallurgy and materials 1999年第1期13卷 61-63,68页

作者： Jiming Hu Jixun Wu Yanping Lu Yanrong zhu (Material science and {2. School, university of science and technology beijing, beijing 100083, china) Univ of science and technology Beijing Beijing China

X-ray diffraction (XRD), ball-disc friction and wearing machine and draw-bead test were introduced to investigat the strcusture and workability of IF sheet steel electrogalvanized deposits prepared from sulphate solution system. It was shown that the picking-up of the zinc coating on die strengthened with the increasing of friction factor which was originally affected by the coating's structure. Duing forming, (00X) planes (X= 2. 4) preferential orientation of zinc deposits increased, which resulted in enhanc ing the coating's friction behaviors. Therefore, the forming mechanism of electrogalvedzed deposit was demonstrated that both friction and the stricking -up behaviors of the coating are intensified simultaneously and affect each other.

关键词： electrogalvanized deposit forming friction factor

Chemical states of the atoms in magnetic multilayers Ta/NiO_x/Ni_(81)Fe_(19)/Ta and Co/AlO_x/Co

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Chinese science Bulletin 2002年第4期47卷 276-279页

作者： YU Guanghua, zhu fengwu & CHAI ChunlinDepartment of {2. Physics, university of science and technology, beijing 100083, china Department of materials Physics University of Science and Technology Beijing China

Ta/NiOx/Ni81Fe19/Ta and Co/AlOx/Co multilay-ers were prepared by rf reactive and dc magnetron sputter-ing. The exchange coupling field (Hex) and the coercivity (Hc) of NiOx/Ni81Fe19 as a function of the ratio of Ar to O2.during the deposition process were studied. The composition and chemical states at the interface region of NiOx/NiFe were also investigated using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that when the ratio of Ar to O2.is equal to 7 and the argon sputtering pressure is 0.57 Pa, the x value is approximately 1 and the valence of nickel is +2. At this point, NiOx is anti-ferromagnetic NiO and the corresponding Hex is the largest. As the ratio of Ar/O2.deviates from 7, the Hex will decrease due to the presence of magnetic impurities such as Ni+3 or metallic Ni at the interface region of NiOx/NiFe, while the Hc will increase due to the metallic Ni. Al layers in Co/AlOx/Co multilayers were also studied by angle-resolved XPS. Our finding is

关键词： NiOx/NiFe exchange coupling Co/AlOx/Co X-ray pho-toelectron spectroscopy (XPS) chemical states.

Structure and magnetic properties of vacuum annealed FePt/Ag nano-multilayers

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Chinese science Bulletin 2003年第3期48卷 236-238页

作者： YANG Tao, YU Guanghua, HWANG Pol & zhu fengwu Department of {2. Physics, university of science and technology beijing, beijing 100083, china Department of materials Physics University of Science and Technology Beijing Beijing 100083 China

FePt/Ag)n nano-multilayers were deposited on MgO(100) single crystal with laser ablation and then sub-jected to annealing. FePt L10 grains with (001) texture and a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for improving the (111) preferential orientation and decreasing the dispersion of the easy axis for magnetiza-tion. The measurement of time decay of magnetization gave rise to an activation volume as small as 6×10-2. m3, showing the promising perspective of being the recording medium for future high density perpendicular recording.

关键词：磁记录介质真空封装 FePt/Ag纳米复合薄膜结构磁学性质

XPS Studies of Chemical States of NiO/NiFe Interface

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Journal of university of science and technology beijing 2001年第4期8卷 270-273页

作者： Guanghua Yu, Chunlin Chai, fengwu zhu, Jimei Xiao, Wuyan Lai 1){2. science and engineering School, university of science and technology beijing, beijing 100083, china 2.Institute of Physics. Chinese Academy of sciences. beijing, 100080, china Univ Sci & Technol beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Chinese Acad Sci Inst Phys Beijing 100080 Peoples R China

Ta/NTiO/NiFe/Ta multilayers were prepared by radio frequency reactive and dc magnetron sputtering. The exchange coupling field between NiO and NiFe reached 9.6 x 10(3) A/m. The compositions and chemical states at the interface region of NiO/NiFe were studied using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique, The results show that there are two thermodynamically favorable reactions at NiO/NiFe interface: NiO+Fe = Ni + FeO and 3NiO+2.e =3 Ni+Fe2.3. The thickness of the chemical reaction area estimated by angle-resolved XPS was about 1-1.5 nm. These interface reaction products appear magnetic defects, and the exchange coupling field H-ex and the coereivity H-c of NiO/NiFe are affected by these defects.

关键词： chemical states exchange coupling field H-ex coercivity H-c X-ray photoelectron spectroscopy (XPS)

SiO_2.Ta interface reaction in magnetic multilayers and its influence on Ta buffer layers

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Chinese science Bulletin 2002年第19期47卷 1601-1603页

作者： YU Guanghua, MA Jidong, zhu fengwu & CHAI ChunlinDepartment of {2. Physics, university of science and technology, beijing 100083, china Institute of Semiconductor, Chinese Academy of sciences, beijing 100083, china Department of materials Physics University of Science and Technology Beijing 100083 China Institute of Semiconductor Chinese Academy of Sciences Beijing 100083 China

Ta is often used as a buffer layer in magnetic multilayers. In this study, Ta/Ni81Fe19/Ta multilayers were deposited by magnetron sputtering on sing-crystal Si with a 300-nm-thick SiO2.film. The composition and chemical states at the interface region of SiO2.Ta were studied using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that there is an "intermixing layer" at the SiO2.Ta interface due to a thermody-namically favorable reaction: 15 SiO2.37 Ta = 6 Ta2.5 + 5 Ta5Si3. Therefore, the Ta buffer layer thickness used to induce NiFe (111) texture increases.

关键词： SiO2.Ta interface interface reaction X-ray photoelectron spectroscopy (XPS).

Study on Tribological Properties of the Rolling Fluid Containing Nano-MoS_2.for Cold Rolling of Steel Strip

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china Petroleum Processing & Petrochemical technology 2011年第1期13卷 64-69页

作者： zhu Guangping Sun Jianlin Wang Bing Wang Yizhu (School of {2. and engineering,university of science and technology beijing,beijing 100083) Univ Sci & Technol beijing Sch Mat & Engn Beijing 100083 Peoples R China

The nano-MoS2.particles were adopted to substitute for the extreme-pressure and anti-wear additives to the rolling fluid for steel *** optimal formulation and technical process for adding nano-MoS2.particles to the rolling fluid were obtained through orthogonal experiments with three factors at three *** tests have led to the following conclusions:(a) the nanoparticles should be added to a base oil with high saponification value;(b) the concentration of nanoparticles in rolling fluid should be equal to 0.6%;and (c) when the reaction time needed for surfactants (oleic acid,for example) to modify the nanoparticles was 40 min,the rolling fluid could have the best tribological *** lubricity of rolling fluid was verified by using a 4-high cold rolling test mill which showed that the rolling fluid with nano-MoS2.particles had the excellent lubricant performance to improve the surface quality of the steel strip *** mechanism of nano-MoS2.particles in the rolling process has been investigated by a series of characterization instruments,which have showed that,with its fullerene-like structure,the nano-MoS2.particles have self-lubricating properties and extra-low friction coefficient,and can easily form a protective film with low shear strength on the surface of friction pairs.

关键词： cold rolling nano-MoS2 strip rolling fluid mechanism