Experimental Studies of Organic Charge Transfer Salts

有机电荷转移盐的实验研究

• 批准号: 9216155
• 负责人: Paul Chaikin
• 金额: $ 45万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-03-01 至 1996-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9216155&HistoricalAwards=false
• 关键词: Experimental; Studies; Organic; Charge; Transfer

The goal of this research is to explore how low dimensions, strong interactions and frustration from applied fields act together to produce interesting states of matter. One such material (Bechgaard salt) exhibits metallic, insulating, antiferromagnetic, density wave, superconducting, non-ohmic, quasi-periodic and Quantum Hall Effect phases as temperature, pressure and magnetic field are varied. Experiments involving magnetic, thermal, elastic, and structural measurements are conducted on normal, superconducting and exotic phases of the quasi-one and quasi-two dimensional organic charge transfer salts. New phenomena found in no other materials also are examined. These include a cascade of magnetic field induced transitions and new forms of quantum oscillations. In addition, the effects of extraordinary magnetic field, up to 65 Tesla, on the behavior of low-dimensional systems are investigated. %%% In this work, electronic properties of highly anisotropic organic conductors are studied. Typically, the conductivity is one million times better along the best conducting direction of the crystal than along the worst. Because the electrons are constrained to move along chains, they interact more strongly with other electrons, thus causing a number of unusual transitions and properties. At room temperature, the materials are metallic. On cooling to liquid helium temperatures, the materials become insulating, magnetic or superconducting. When magnetic fields are applied and oriented in different directions relative to the chains, striking changes in material properties are noted. The object of these studies is to understand the basic competition between metals and insulator, magnet and superconductor in a molecular system. The successful completion of the proposed studies ultimately will lead to the development of new materials for fabrication of new electronic devices.

这项研究的目标是探索低维度、强相互作用和应用领域的挫折如何共同作用以产生有趣的物质状态。 一种这样的材料（贝希加德盐）随着温度、压力和磁场的变化而表现出金属相、绝缘相、反铁磁相、密度波相、超导相、非欧姆相、准周期相和量子霍尔效应相。 涉及磁、热、弹性和结构测量的实验是在准一维和准二维有机电荷转移盐的正常相、超导相和奇异相上进行的。 还检查了其他材料中没有发现的新现象。 其中包括一系列磁场引起的跃迁和新形式的量子振荡。 此外，还研究了高达 65 特斯拉的异常磁场对低维系统行为的影响。 %%% 在这项工作中，研究了高度各向异性有机导体的电子特性。 通常，沿晶体最佳导电方向的电导率比沿最差方向的电导率高一百万倍。 由于电子被限制沿着链移动，因此它们与其他电子的相互作用更强烈，从而导致许多不寻常的跃迁和特性。 在室温下，该材料是金属的。 当冷却到液氦温度时，材料变得绝缘、磁性或超导。 当磁场相对于链条沿不同方向施加和定向时，材料特性会发生显着变化。 这些研究的目的是了解分子系统中金属与绝缘体、磁体和超导体之间的基本竞争。 拟议研究的成功完成最终将导致用于制造新电子设备的新材料的开发。