Electronic Properties of Transition Metal Oxides

该项目的重点是研究面内和面外正常状态的导电性，使用极高质量的氧化铜超导体和层状锰氧化物单晶。 我们对高转变温度Tc铜氧化物中正常态电荷沿着CuO（2）面和面外方向输运的物理理解还远未完成。 这在一定程度上是由于缺乏全面的实验研究，这些属性的演变与掺杂在整个范围内的化学计量：欠掺杂，最佳和过度掺杂制度。 对于铜酸盐，重点将是在正常状态下的相变传导整个相图，其中包括绝缘，欠掺杂，和过掺杂制度。 提出了一系列的电输运和磁化研究。 这些数据将被分析，以获得有关电子传输和传导机制的信息。 层状锰氧化物具有延伸相图，其中包括几个相变。这些热力学相变对电荷输运有很强的影响。 将通过电荷输运和磁化测量对锰氧化物的导电机制进行全面研究。 这项研究将显着提高我们的铜酸盐和锰氧化物的电荷传导的基本理解，解决这些系统的物理中的关键问题。 更广泛地说，从这个基础研究的结果可以提供洞察适当的掺杂方案，以促进铜酸盐和锰氧化物的电子传感器和设备，如磁场传感器，甚至计算机逻辑器件的应用。 这一高度跨学科的项目有助于教育和培训博士生和本科生，以及合作机构的博士后研究人员。 参与者在这项研究计划中获得的专业知识的多样性是当今以知识为基础，技术驱动的经济中的一个重大优势，有利于未来在工业，政府或学术界的职业生涯。这个实验研究项目关注的是高温超导体和层状锰氧化物的不寻常的电学性质和行为。高温超导体即使在正常状态下，其导电方式也与铜和硅等典型导体截然不同。 此外，锰氧化物中的电传导受到热力学相变的强烈影响。 本计画将大大增进我们对铜酸盐及锰氧化物电性行为的基本了解。 阐明这些新颖的电学行为可能有助于这些材料用于电子传感器和器件（例如磁场传感器或甚至计算机逻辑器件）的最终应用。 该项目为跨学科项目中的研究生提供了极好的研究和教育机会。 它涉及少数群体研究生，他们从事论文研究并接受优秀的培训，有利于未来在工业，政府或学术界的职业生涯。与罗马尼亚和西班牙科学家的国际合作，需要执行该项目的一部分，有助于国家的研究和教育基础设施。

This project is focused on the investigation of in-plane and out-of-plane normal-state electrical conduction, using extremely high quality single crystals of selected copper-oxide superconductors and layered manganites. Our understanding of the physics of the normal-state charge transport along the CuO(2) planes and in the out-of-plane direction in the high transition temperature Tc cuprates is still far from complete. This is in part due to the scarcity of comprehensive experimental studies on the evolution of these properties with doping across the full range of stoichiometry: under-doped, optimally-, and over-doped regimes. For the cuprates, the emphasis will be on the transformation of the normal-state conduction across the phase diagram, which includes insulating, under-doped, and over-doped regimes. A series of electrical transport and magnetization investigations are proposed. The data will be analyzed for information about electronic transport and conduction mechanisms. Layered manganites have a reach phase diagram, which includes several phase transitions. These thermodynamic phase transitions have a strong effect on the charge transport. A comprehensive study of the conduction mechanism in manganites will be undertaken through charge transport and magnetization measurements. This research will significantly enhance our fundamental understanding of charge conduction in cuprates and manganites by addressing key issues in the physics of these systems. More broadly, the results from this basic investigation may provide insight into appropriate doping schemes to facilitate applications of cuprates and manganites for electronic sensors and devices such as magnetic field sensors or even computer logic devices. This highly interdisciplinary project contributes to the education and training of doctoral and undergraduate students, as well as postdoctoral researchers at the institutions, which are part of the collaboration. The diversity of the expertise gained by the participants in this research program is a substantial advantage in today's knowledge based, technology driven economy, being beneficial to a future career in industry, government, or academia. This experimental research project concerns the unusual electrical properties and behavior of high temperature superconductors and layer manganites. The high temperature superconductors, even in the normal state, conduct electricity in ways that are very different from typical conductors such as cooper and silicon. Also, the conduction of electricity in manganites is strongly affected by thermodynamic phase transitions. This project will significantly enhance our fundamental understanding of the electrical behaviors of cuprates and manganites. Clarifying these novel electrical behaviors may contribute to eventual applications of these materials for electronic sensors and devices such as magnetic field sensors or even computer logic devices. This project offer excellent research and education opportunities for graduate students within an interdisciplinary program. It involves minority-group graduate students who pursue thesis research and receive excellent training beneficial to a future career in industry, government, or academia. The international collaborations with scientists from Romania and Spain, needed to carry out parts of this project, contribute to the nation's infrastructure for research and education.