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Magnetic Coupling in La_(0.67)Ca_(0.33)MnO_3/La_(0.67)Sr_(0.33)CoO_3/La_(0.67)Ca_(0.33)MnO_3 Trilayer Films

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Journal of Rare Earths 2004年第6期22卷 887-890页

作者：赵昆李昊黄康权 Magnetoelectronics Laboratory School of Physics Science and Information Technology Liaocheng University Department of Physics Chinese University of Hong Kong Hong Kong 00852 China

The perovskite La_(0.67)Ca_(0.33)MnO_3/La_(0.67)Sr_(0.33)CoO_3/La_(0.67)Ca_(0.33)MnO_3 trilayers were fabricated by a facing-target sputtering technique and their magnetotransport properties were investigated. The magnetoresistance is dependent on spacer thickness and dramatically decreases when La_(0.67)Sr_(0.33)CoO_3 layer is thick enough because of its short-circuiting effect. Different from La_(0.67)Ca_(0.33)MnO_3 single layer, trilayer films with thin La_(0.67)Sr_(0.33)CoO_3 spacer have the enhanced metal-semiconductor transition temperature (T_(MS)) of La_(0.67)Ca_(0.33)MnO_3 layers. The magnetic coercivity H_C shows a nonmonotonic behavior with changing the spacer layer thickness at 230 K. The waist-like hysteresis indicates that there is an indirect exchange coupling between the top and bottom La_(0.67)Ca_(0.33)MnO_3 layers across the spacer La_(0.67)Sr_(0.33)CoO_3 layer.

关键词： colossal magnetoresistance hysteresis loop magnetic coupling rare earths

Output performance optimization for RTD fluxgate sensor based on dynamic permeability

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Science China(Information Sciences) 2016年第11期59卷 182-194页

作者： Yanzhang WANG Shujun WU Hao LU Defu CHENG Chen CHEN Na PANG Yunxia WAN Zhijian ZHOU Siyu CHEN College of Instrumentation and Electrical Engineering Jilin University Key Laboratory of Geo-Exploration Instrumentation Ministry of Education Jilin University

The output performance of residence times difference(RTD) fluxgate may vary under different driving conditions(driving currents and frequencies) and core materials. To optimize the RTD fluxgate and simplify its design process, an analytical model is employed to select the parameters and identify the effective factors that dominate the performance. The dynamic permeability parameters(Pi), which reflect the changes in the magnetization curve, are mathematically analyzed in detail. The linear variation functions of Pi in different driving conditions are fitted by using the dynamic arctangent hysteresis model. Consequently, the selection of driving conditions and core materials, which are assessed by comparing the experiment and simulation results,has an important role in achieving the optimal output performance of the RTD fluxgate.

关键词： RTD fluxgate hysteresis loop analysis of dynamic permeability simulation output response

Magnetic and Electrical Behavior of MnTe_(1-x)Sb_x Alloys

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Journal of Materials Science & Technology 2011年第1期27卷 64-68页

作者： X.He Y.Q.Zhang Z.D.Zhang Shenyang National Laboratory for Materials Science Institute of Metal Researchand International Center for Materials PhysicsChinese Academy of SciencesShenyang 110016China

The structure,specific heat,magnetic and electrical properties of MnTe1-xSbx（x=0,0.1,0.15,0.2 and 0.25） alloys have been investigated.The MnTe1-xSbx alloys crystallize in a hexagonal NiAs-type structure,and the impurity of MnSb phase appears when x≥0.15.The MnTe0.9Sb0.1 compound exhibits ferrimagnetic behavior with hysteresis loops even at 350 K,showing that the magnetic properties of MnTe compound are very sensitive to little compositional change.The ferromagnetism in the MnTe1-xSbx alloys with higher Sb contents may be attributed to the impurity of MnSb phase.Energy dispersive X-ray spectroscopy analysis on the MnTe0.9Sb0.1 compound indicates that Sb is very difficult to dope into the lattice of MnTe.So the anomaly of resistivity at 300 K of MnTe0.9Sb0.1 and the peak of specific heat around 304 K of all the alloys are thought to be related with the antiferromagnetic interactions of MnTe-based lattice.

关键词： Electronic transport property hysteresis loop Specific heat

Magnetic properties of sputtered anisotropic Pr–Fe–B thin films with different structures and antiferromagnetic materials

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Rare Metals 2016年第12期35卷 926-929页

作者： Fang Yang Wei Liu Zhi-Dong Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research and International Centre for Materials PhysicsChinese Academy of Sciences Superconducting Materials Research Center Northwest Institute for Nonferrous Metal Research

Anisotropic Pr-Fe-B films with soft-magnetic layer （Fe） and/or antiferromagnetic layer （Mn, FeMn or MnO） were prepared by direct-current （DC） magnetron sputtering on Si （100） substrates heated at 650℃. The influence of four types＇ different structures on the magnetic properties of Pr-Fe-B films was investigated. The phase and magnetic properties were characterized by means of X-ray diffraction （XRD） and superconducting quantum interference device （SQUID）. Addition of anti-ferromagnetic layer enhances both the coercivity and the remanence ratios of Pr-Fe-B films with suitable structures. The interface number increases and the antiferromagnetic-ferromagnetic exchange interaction is likely to become stronger, which affect the improvement of magnetic properties. To further understand the influence of structures with soft-magnetic Fe layer and/or antifer- romagnetic FeMn layer on the magnetic properties of Pr-Fe-B hard-magnetic films, the thickness of Pr-Fe-B layer was designed to decrease from 600 to 50 nm. The improvement of magnetic properties becomes obvious in Mo（50 nm）/Pr-Fe-B（25 nm）Mo（2 nm）FeMn（20 nm）Mo （2 nm）Pr-Fe-B（25 nm）/Mo（50 rim） film.

关键词： Magnetic materials Thin films Coercivity hysteresis loop Sputtering

Compensation temperature and hysteresis behaviors of a graphene-like bilayer:Monte Carlo Study

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Communications in Theoretical Physics 2023年第4期75卷 131-143页

作者： Bo-chen Li Dan Lv Wei Wang Lei Sun Zi-Ming Hao Jia Bao School of Science Shenyang University of TechnologyShenyang 110870China School of Environmental and Chemical Engineering Shenyang University of TechnologyShenyang 110870China

Using the Monte Carlo method,the compensation temperature and hysteresis loops of a ferrimagnetic mixed spin-3/2 and spin-5/2 Ising-type graphene-like bilayer are investigated induced by different physical parameters such as crystal field,exchange coupling,external magnetic field,and temperature.The variations of magnetization,magnetic susceptibility,specific heat,and internal energy with the change of temperature are discussed.In addition,we also plot the phase diagrams including transition temperature and compensation temperature.Finally,multiple hysteresis loops under certain parameters are given.

关键词： graphene-like bilayer magnetization compensation temperature hysteresis loop Monte Carlo method

Novel Nanotrees of Crystalline Nickel Formed via Electrolytic Approach

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Nano-Micro Letters 2011年第4期3卷 264-269页

作者： Jian Wang Liying Zhang Liangming Wei Chuanhai Jiang Yafei Zhang Key Laboratory for Thin Film and Microfabrication of the Ministry of Education Research Institute of Micro/Nano Science and TechnologySchool of Materials Science and EngineeringShanghai Jiao Tong University

Tree-shaped nickel nanocrystals with long main trunk and highly ordered branches were prepared via electrolytic method in ethylene glycol solution. The morphology and structures of nanotrees of crystalline nickel can be controlled by the processing of the surfactant(PVP) and electrolytic voltage. Magnetic property measurements at room temperature indicated that the as-prepared nanotrees of crystalline nickel possess higher saturation magnetism(MS) and coercivity(HC) than those of corresponding bulk nickel materials.

关键词： Nickel crystals Nanotrees hysteresis loop Thermogravimetric analysis

Study on the thixotropy and structural recovery characteristics of waxy crude oil emulsion

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Petroleum Science 2021年第4期18卷 1195-1202页

作者： Li-Ping Guo Xue Han Yun Lei Lei Wang Peng-Fei Yu Shuang Shia Key Laboratory of Enhanced Oil Recovery Ministry of EducationNortheast Petroleum UniversityHeilongjiang163000China Jiangsu Key Laboratory of Oil and Gas Storage&Transportation Technology Changzhou UniversityJiangsu213164China Exploration and Development Research Institute Daqing Oil Field Company LtdDaqingHeilongjiang163712China

Waxy crude oil emulsion has thixotropic properties at the temperature near gel point,which is a macromechanical characterization of the structure failure and recovery of waxy crude oil emulsion.In this paper,the thixotropic behaviors of waxy crude oil emulsion near gel point were studied using hysteresis loop formed by stress linear increase and decrease,as well as the structural recovery characteristics.The influence of the loading conditions and water content on the thixotropy of waxy crude oil emulsion were analyzed with hysteresis loop area.The concept of"structural recovery"was introduced to study the degree of structural recovery after different stewing,and influencing factors were taken into account.Results have shown that for waxy crude oil emulsion,the failure to fully restore of the structure after lysis is the cause of the formation of hysteresis loop,and the loading conditions will not affect the strength of thixotropy and the degree of structural recovery.Additionally,the dispersed phase droplets weaken the thixotropy and structure recovery characteristics of waxy crude oil emulsion,and the greater the water content,the weaker the thixotropy.The findings can help to better understand the safe and economic operation of waxy crude oil-water pipeline transportation.

关键词： Waxy crude oil Emulsion Thixotropic properties Structural recovery hysteresis loop

Cycling Hardening and Serration Yielding of Fe-Ni-Cr Alloy at High Temperature under Out-phase TMF

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Journal of Wuhan University of Technology(Materials Science) 2009年第3期24卷 428-431页

作者：何庆复 Department of Mechanical Engineering Beijing Jiaotong University

Behaviour of hardening and serration yield of a Fe-Ni-Cr alloy under isothermal cycling （ISC） and out-phase TMF was studied on the basis of varied hysteresis loops. Cycling hardening and serrated yielding for ISC depend on the temperature and the total strain range, stronger hardening with serrated yielding at higher strain range under ISC at 600 ℃, but no hardening and serrated yielding occurred under ISC at 800 ℃. Stronger hardening with stress serration occurred at the thermal path going to the lowest temperature, no stress serration occurred at the highest temperature under the out-phase. The hardening also depends on the total strain range, higher total strain range with lower cycling temperature resulted in a stronger hardening and remarkable serration yielding behavior. Weaker hardening without serrated yielding occurred at near 800℃ may due to an obvious cycling stress drop under out-phase TMF. Change in the shape of the hysteresis loops also expresses the degree of the damage of the tested alloy under out-phase and ISC.

关键词： hysteresis loop cycling hardening serration yield out-phase isothermal cycling

Research on seismic performance and design method of combined steel lead energy dissipation structure(Ⅰ)

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Journal of Harbin Institute of Technology(New Series) 2010年第3期17卷 376-382页

作者：颜学渊张永山王焕定黄东阳辛亚军 School of Civil Engineering Harbin Institute of Technology College of Civil Engineering Fuzhou University Earthquake Engineering Research & Test Center Guangzhou University School of Civil Engineering and Mechanics Yanshan University

A new combined steel lead damper (NCSLD) was presented. Construction and working mechanism of NCSLD were introduced,pseudo-static tests of the small size dampers which would be used in the subsequent shaking table tests were carried out for the study of mechanical properties of NCSLD using electro-hydraulic servo press-shear machine. Processing technology of the damper was improved. Shaking table tests under two-dimensional excitation on structural aseismic control of a one-story structure model were carried out using the small size NCSLD; parameters of the structure and shaking table were also introduced. Results indicate that process improvement is beneficial to the implementation of working mechanism of the damper,NCSLD has full hysteresis loop which takes on bilinearity,NCSLD has obvious energy dissipation effect and it can control structural seismic response effectively.

关键词： structural earthquake-resistance new combined steel lead damper (NCSLD) earthquake simulation shaking table test seismic response hysteresis loop