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YBCO/lcmo双层膜微结构的HREM研究

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电子显微学报 2000年第4期19卷 411-412页

作者：王明光李斗星熊光成叶恒强中国科学院金属所固体原子像开放研究实验室沈阳110015 北京大学物理系北京100871

La0.7Ca0.3MnO3(lcmo)薄膜是一种典型的巨磁阻(CMR)材料,在信息存储领域具有广阔的应用前景[1,2](如磁记录读出磁头等),而lcmo与高温超导材料YBa2Cu3O7(YBCO)组成的双层薄膜更显示出许多奇特的物理性质[3].由于薄膜的微结构对其物理性... 详细信息

La0.7Ca0.3MnO3(lcmo)薄膜是一种典型的巨磁阻(CMR)材料,在信息存储领域具有广阔的应用前景[1,2](如磁记录读出磁头等),而lcmo与高温超导材料YBa2Cu3O7(YBCO)组成的双层薄膜更显示出许多奇特的物理性质[3].由于薄膜的微结构对其物理性能有很大影响,因此研究薄膜的微结构有助于对此类材料的磁性与超导电性相关机制的理解.本文利用高分辨电子显微镜系统地研究了YBCO/lcmo双层薄膜的显微结构.

关键词： YBCO lcmo 双层膜微结构 HREM

Microstructural Characteristics of La_(0.7)Ca_(0.3)MnO_3 Films and Multilayers

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Journal of Materials Science & Technology 2000年第6期16卷 601-604页

作者： Mingguang WANG, DouXing LI, Lianlong HE and Hengqiang YE (Laboratory of Atomic Imaging of Solid, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China) Guangcheng XIONG (Department of Physics and Mesoscopic Physics National Labo Lab. of Atomic Imaging of Solid Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110015 China

La0.7Ca0.3MnO3 (lcmo) films and La0.7Ca0.3MnO3/Gd0.7Ca0.3MnO3 (lcmo/GCMO) multilayers have been prepared by pulsed laser deposition. The microstructures of both systems were investigated by transmission electron microscopy (TEM). The main structure of the films and the multilayers was monoclinic with a unit cell of size 2ap x-2ap. x -2ap, where ap is the lattice constant of single perovskite crystal. The lcmo films were composed of three-dimension multitwinning domains, while the lcmo/GCMO multilayers showed two-domain structure. In lcmo/GCMO multilayers, lcmo layers were coherent with GCMO layers and the interfaces between lcmo and GCMO layers were free from mismatch dislocation, which resulted in highly strained multilayerd structures.

关键词： lcmo Microstructural Characteristics of La MnO3 Films and Multilayers Ca

Current-Induced Reversible Resistance Jumps in La_(0.8)Ca_(0.2)MnO_3 Microbridge

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Chinese Physics Letters 2016年第5期33卷 71-74页

作者：翟章印解其云陈贵宾吴小山高炬 Department of Physics and Jiangsu Key Laboratory for Chemistry of Low-Dimensional MaterialsHuaiyin Normal University Laboratory of Solid State Microstructures and Department of PhysicsNanjing University Department of Physics The University of Hong Kong Key Laboratory of Radio Frequency and MicroNano Electronics of Jiangsu Province

Two spatially confined La0.8Ca0.2MnO3（lcmo） microbridges with different widths, starting from a single lcmo fihn （3mm×5 mm）, are fabricated by optical lithography. A second new and robust metal-insulator transition （MIT） peak at about 75K appears, in addition to the normal MIT at 180 K observed in the standard lcmo film. When the two bridges are processed by currents of high densities, interesting reversible resistance jumps are excited only around the new peak. A stronger dependence of resistance jump on current excitation is found for the bridge with a smaller width. The temperature driven transition between new excited multiple metastable states are involved to explain the interesting low-temperature ultra-sharp jumps.

关键词： lcmo is on of in Ca

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超巨磁阻测辐射热仪

物理学报 2000年第8期49卷 1567-1573页

作者：顾梅梅张鹏翔李国桢昆明理工大学材料系昆明650051

基于超巨磁阻 (CMR)材料在金属绝缘体 (M I)转变点附近的巨大电阻变化 ,设计并测试了一种新型超巨磁阻测辐射热仪 (CMRbolometer) .用外延法生长的La0 .67Ca0 .3 3 MnO3薄膜作为测辐射热仪的辐射敏感元件 ,测量了该器件对黑体和He Ne... 详细信息

基于超巨磁阻 (CMR)材料在金属绝缘体 (M I)转变点附近的巨大电阻变化 ,设计并测试了一种新型超巨磁阻测辐射热仪 (CMRbolometer) .用外延法生长的La0 .67Ca0 .3 3 MnO3薄膜作为测辐射热仪的辐射敏感元件 ,测量了该器件对黑体和He Ne激光器的光学响应 .所测的信号、噪声都随调制频率的上升而下降 ,但对于He Ne激光源 ,它的信噪比却没有明显的改变 .测量了薄膜铁磁金属态和顺磁绝缘态的信号温度关系 ,最强的信号出现在靠近M I转变点 (居里点 )附近的铁磁态范围 .由于薄膜的居里点温度TC 随制备条件的不同 ,可从 70K变化到 35 0K ,所以该器件的最大特点是能在室温下工作 .从这个角度看 ,它可弥补高温超导测辐射热仪只能工作于液氮温区的缺点 .初步测量显示 ,该器件的探测率接近 10 7cmHz1/ 2 W-1,热响应时间约为 2 0ms.与高温超导测辐射热仪相比 ,超巨磁阻测辐射热仪的时间常量偏大 ,探测率偏低 .然而。

关键词：超巨磁阻测辐射热仪 lcmo 红外超导

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钙钛矿型锰氧化合物的光电效应

红外与毫米波学报 1998年第2期17卷 157-160页

作者：郝建华曾宪庭黄康权华中理工大学光电子工程系香港中文大学物理系

报道了Ｌａ０．６７Ｃａ０．３３ＭｎＯδ单晶薄膜的光响应．这类钙钛矿型锰氧化物响应为测辐射热模式．新型测辐射热计宽波段光吸收系数高．调整掺杂组份和氧计量比可获得合适工作温区．此外，还报道了样品的噪声特性．

关键词： lcmo 薄膜光探测辐射热钙钛矿型光电效应

自旋玻璃锰氧化物La_(0.67)Ca_(0.33)(Mn,Fe)O_3中的分步磁化和超大磁电阻

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物理学报 1999年第4期48卷 757-762页

作者：王志宏蔡建旺中国科学院物理研究所和凝聚态物理中心

在Ｍｎ位替代钙钛石氧化物Ｌａ０．６７Ｃａ０．３３（Ｍｎ，Ｆｅ）Ｏ３中观察到分步磁化现象，并在临界场附近获得大于１０４％的超大磁电阻效应．指出自旋玻璃相中反铁磁团簇在外磁场下的熔化是分步磁化的物理起因．

关键词： lcmo 分步磁化超大磁电阻钙钛石氧化物

Mn位上Cu掺杂对La-Ca-Mn-O系统液氮温度磁电阻效应的影响

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物理学报 1998年第6期47卷 965-969页

作者：孙霞汤萍黄真陈岳李广陈治友刘智明袁松柳中国科学院合肥等离子体物理研究所

实验研究了Ｍｎ位上Ｃｕ掺杂对Ｌａ２／３Ｃａ１／３Ｍｎ１－ｘＣｕｘＯｙ单相块材液氮温度磁电阻效应的影响．结果表明，在最佳掺杂（ｘ≈０１５）的情况下，样品表现出非常明显的磁电阻效应，且磁电阻的主要变化发生在１Ｔ以下的低... 详细信息

实验研究了Ｍｎ位上Ｃｕ掺杂对Ｌａ２／３Ｃａ１／３Ｍｎ１－ｘＣｕｘＯｙ单相块材液氮温度磁电阻效应的影响．结果表明，在最佳掺杂（ｘ≈０１５）的情况下，样品表现出非常明显的磁电阻效应，且磁电阻的主要变化发生在１Ｔ以下的低磁场下；当磁场增加到６Ｔ时，该样品的磁电阻效应比高达约５×１０４％，相对于偏离最佳掺杂的样品，提高了近三个数量级．

关键词： lcmo 超导体磁电阻效应铜掺杂液氮温度

Magnetoelectric coupling across the interface of multiferroic nanocomposites

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Science China Materials 2015年第2期58卷 143-155页

作者：姚携菲马静林元华南策文张金星 Department of Physics Beijing Normal University School of Material Science and Engineering Tsinghua University

In recent decades, magnetoelectric effect in multiferroic materials has attracted extensive attention owing to the upcoming demands for new-generation multi-functional magnetoelectronic devices, such as transducer, sensor and so on. This gives people a strong push to explore the multiferroic materials with a reduced dimension and effective coupling between electric and magnetic orderings, especially at room temperature. Due to the weak magnetoelectric coupling strength in sing-phase multiferroic materials, scientists start to design nanocomposites and artificial nanostructures with strong coupling among order parameters(lattice, charge, spin and orbital). In this review, we will introduce recent major progresses of magnetoelectric coupling in multiferroic nanocomposites across their interfaces from the following four aspects: strain effect, charge transfer, magnetic exchange interaction and orbital hybridization, based on their coupling mechanisms. Through a full understanding of the above coupling among these orderings, it is possible to achieve the nanoscale modulation of magnetization(ferroelectric polarization) by external electric(magnetic) field. Apart from the magnetoelectric coupling, those artificially functional nanocomposites provide us a platform to explore and study the emerging physical phenomena so that we can design self-assembled nanostructures to tailor novel functionalities in future applications.

关键词：磁电耦合效应 ME LSMO lcmo BTO XMCD BFO 纳米复合材料多铁性复合材料

Tunable magnetic and electrical behaviors in perovskite oxides by oxygen octahedral tilting

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Science China Materials 2015年第4期58卷 302-312页

作者：高雅王建军伍亮鲍善永沈洋林元华南策文 School of Materials Science and Engineering and State Key Laboratory of New Ceramics and Fine Processing Tsinghua University Department of Materials Science and Engineering Pennsylvania State University University Park

The oxides with perovskite structure possess abundant physical properties, such as magnetism, dielectricity, photoelectricity, ferroelectricity, etc. The oxygen ions in the perovskite unit cell constitute an octahedral distribution. The deformation or tilting of the special oxygen octahedra structure leads to new performances or properties change. Here, we give a review of the relationship between magnetic and electrical behaviors and oxygen octahedral tilting in several typical perovskite oxides. An understanding of how to tune these properties by controlling the tilting during the sample growth can more effectively guide the design of new structures for high performance and inspiring their potential applications.

关键词： BFO 八面体多面体 lcmo MFe BNT