• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Influence of the phase separation on the transport properties of the charge ordered colossal magnetoresistance manganites.
【24h】

Influence of the phase separation on the transport properties of the charge ordered colossal magnetoresistance manganites.

机译：相分离对电荷有序巨磁电阻锰矿输运性质的影响。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Transition-metal oxides have long been the subject of study, because they exhibit a wide range of exotic and still incompletely understood structural, magnetic and electronic properties. This behavior cannot be explained within the context of the usual one-electron band theory that accounts well for the properties of most other solids, indicating the importance of strong electron-electron and electron-lattice correlations.; Recently, attention has become focused on a certain class of manganese oxides, the manganite perovskites. The current burst of activity was stimulated by reports of spectacularly large—“colossal” magnetoresistance in this family of compounds. In these materials, the interaction between the electrons and lattice vibrations (phonons) is unusually strong, leading to a wide range of striking physical phenomena such as magnetic ordering, charge ordering and the metal-insulator transition. These materials therefore provide an unprecedented opportunity to study the physics of systems in which a high density of electrons is strongly coupled to phonons.; The primary concern of this work is an experimental study of a poorly understood metal-insulator transition in the charge-ordered Colossal Magnetoresistance manganites. It mainly comprises the electrical transport and magnetization measurements, l/f and the telegraph noise measurements and the polarized optical microscopy of CMR systems at low temperatures.; One of the important results of this work is demonstration of the percolative metal-insulator transition in CMR materials. In the course of this research, it was also found that inhomogeneous phases in manganites exhibit slow mesoscopic non-equilibrium fluctuations—the telegraph noise. This finding confirms the percolation scenario of the metal-insulator transition and shows that the percolation in CMR has more complicated character than the conventional percolation.; Finally, we demonstrate that the charge-ordered manganites are typical martensitic systems. Our studies revealed a remarkable grain size effect in these systems and, therefore, demonstrated a leading role of the martensitic accommodation strain in defining the electronic properties of charge-ordered manganites.
机译：过渡金属氧化物长期以来一直是研究的主题，因为它们表现出范围广泛的奇特且仍未完全理解的结构，磁性和电子性质。这种行为不能在通常解释大多数其他固体特性的单电子带理论的背景下加以解释，这表明了强电子-电子和电子-晶格相关性的重要性。近来，注意力已经集中在特定种类的锰氧化物上，即锰钙钛矿。有关该化合物家族中巨大的“巨大”磁阻的报道刺激了当前的活动。在这些材料中，电子与晶格振动（声子）之间的相互作用异常强，从而导致了许多惊人的物理现象，例如磁序，电荷序和金属-绝缘体跃迁。因此，这些材料提供了前所未有的机会来研究其中高密度电子与声子强烈耦合的系统的物理性质。这项工作的主要关注点是对电荷排序的巨大磁阻锰矿中金属-绝缘体转变了解不多的实验研究。它主要包括在低温下CMR系统的电传输和磁化测量值， l / f 以及电报噪声测量值和偏振光学显微镜。这项工作的重要成果之一就是证明了CMR材料中的渗透性金属-绝缘体过渡。在研究过程中，还发现锰矿中的不均匀相表现出缓慢的介观非平衡波动（电报噪声）。该发现证实了金属-绝缘体过渡的渗滤情况，并表明CMR中的渗滤具有比常规渗滤更复杂的特性。最后，我们证明了带电荷的锰矿是典型的马氏体系统。我们的研究揭示了这些体系中显着的晶粒尺寸效应，因此证明了马氏体适应应变在定义带电荷的锰铁矿的电子性能方面的主导作用。

著录项

  • 作者

    Podzorov, Vitaly.;

  • 作者单位

    Rutgers The State University of New Jersey - New Brunswick.;

  • 授予单位 Rutgers The State University of New Jersey - New Brunswick.;
  • 学科 Physics Condensed Matter.
  • 学位 Ph.D.
  • 年度 2002
  • 页码 79 p.
  • 总页数 79
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 O49;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号