Electronic Properties of High Temperature Superconductors

高温超导体的电子特性

• 批准号: 9801990
• 负责人: Carmen Almasan
• 金额: $ 24万
• 依托单位: Kent State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2004-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9801990&HistoricalAwards=false
• 关键词: Electronic; Properties; Temperature; Superconductors

w:\awards\awards96\*.doc 9801990 Almasan This experimental research project is at the forefront of transport studies to clarify the unusual normal state properties of cuprates. The work focuses on anisotropy of electrical conduction in in-plane and out-of-plane directions, using extremely high quality and well-characterized single crystals of doped cuprates. The PI will measure the doping, temperature and magnetic field dependences of these conductivity anisotropies. The data will be analyzed for information about electronic structure and conduction mechanisms. Single crystals of YPrBa2Cu3O7 and TlSr2LuCaCu2Oy of variable dopings will be investigated. C-axis transport mechanisms will be investigated by comparing behavior in systems with and without chains. Evidence will be sought for a possible energy gap in the normal state spectrum of the CuO chains. Normal state conduction in strongly off-stoichiometry (under-doped and over-doped) cuprates will be probed by suppressing superconductivity with magnetic fields. Some of the work will be carried out at the NSF-supported National High Magnetic Field Laboratory in Tallahassee FL. This work is expected to advance fundamental understanding of the normal state conduction properties and electronic structure in the cuprates. More broadly, the results from this basic investigation may include fundamental new physical effects and also may provide insight into appropriate doping schemes to facilitate applications of cuprates for electronic sensors or devices. This highly interdisciplinary project strongly involves minority-group graduate students who pursue thesis research at both laboratory locations, and receive excellent training beneficial to a future career in industry, government or academia. %%% This experimental research project is concerns the unusual electrical properties and behavior of metallic oxides containing copper oxide planes. Some of these materials are high temperature superconductors, for example YBa2Cu3O7 which has a superconducting transition temperature of about 92 degrees on the Kelvin scale. The "normal state" properties of these conducting oxides at high temperatures or when the superconductivity is destroyed by an applied magnetic field, are the topics of this research. There are suggestions that these materials, even in the normal state, conduct electricity in ways that are very different from typical electrical conductors such as copper and silicon. Clarifiying these novel electrical behaviors may contribute to eventual applications of these materials in electronic devices such as magnetic field sensors or even computer logic devices. Some of the work will be carried out at the NSF-supported National High Magnetic Field Laboratory in Tallahassee FL. This highly interdisciplinary project strongly involves minority-group graduate students who pursue thesis research at both laboratory locations, and receive excellent training beneficial to a future career in industry, government or academia. ***

w:\awards\awards96\*.doc 9801990 Almasan 该实验研究项目处于输运研究的前沿，旨在阐明铜酸盐不寻常的正常状态特性。 这项工作的重点是使用质量极高且特性良好的掺杂铜酸盐单晶，研究面内和面外方向的导电各向异性。 PI 将测量这些电导率各向异性的掺杂、温度和磁场依赖性。 将分析数据以获取有关电子结构和传导机制的信息。 将研究不同掺杂的 YPrBa2Cu3O7 和 TlSr2LuCaCu2Oy 单晶。将通过比较有链和无链系统的行为来研究 C 轴传输机制。 我们将寻找 CuO 链正常态谱中可能存在能隙的证据。将通过用磁场抑制超导性来探测强偏离化学计量（掺杂不足和过度掺杂）铜酸盐中的正常态传导。 部分工作将在美国国家科学基金会支持的位于佛罗里达州塔拉哈西的国家高磁场实验室进行。 这项工作有望促进对铜酸盐正常状态导电特性和电子结构的基本理解。 更广泛地说，这项基础研究的结果可能包括基本的新物理效应，也可能提供对适当掺杂方案的深入了解，以促进铜酸盐在电子传感器或设备中的应用。 这个高度跨学科的项目强烈涉及少数群体研究生，他们在两个实验室地点进行论文研究，并接受有益于未来在工业界、政府或学术界职业生涯的良好培训。 %%% 该实验研究项目涉及包含氧化铜平面的金属氧化物的不寻常的电性能和行为。其中一些材料是高温超导体，例如 YBa2Cu3O7，其超导转变温度约为开尔文温度 92 度。这些导电氧化物在高温下或超导性被外加磁场破坏时的“正常状态”特性是本研究的主题。有人认为，即使在正常状态下，这些材料的导电方式也与铜和硅等典型电导体非常不同。阐明这些新颖的电学行为可能有助于这些材料在电子设备（例如磁场传感器甚至计算机逻辑设备）中的最终应用。部分工作将在美国国家科学基金会支持的位于佛罗里达州塔拉哈西的国家高磁场实验室进行。这个高度跨学科的项目强烈涉及少数群体研究生，他们在两个实验室地点进行论文研究，并接受有益于未来在工业界、政府或学术界职业生涯的良好培训。 ***