CAREER: Spectroscopic Studies of Magnetically Driven Phase Transitions in Organic & Inorganic Solids

职业：有机物中磁驱动相变的光谱研究

• 批准号: 9623221
• 负责人: Janice Musfeldt
• 金额: $ 30.95万
• 依托单位: SUNY at Binghamton
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2001-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9623221&HistoricalAwards=false
• 关键词: CAREER; Spectroscopic; Studies; Magnetically; Driven

Abstract 9623221 Musfeldt This five-year proposal is concerned with gaining further information on magnetically driven phase transitions in low-dimensional organic and inorganic solids and expanding materials chemistry coursework at the State University of New York. In general, the low-temperature spectroscopic response of several prototypical compounds in an external magnetic field will be investigated. These compounds are well-known to display spin-density wave and spin-Peierls type phase transitions, and many other interesting physical properties. In each case, the Principal investigator and graduate students will: 1. completely characterize the optical constants of these systems using low-temperature polarized infrared and optical spectroscopies in the vicinity of the phase transition, 2. evaluate optical constants and fundamental materials parameters, such as correlation parameters and electron-molecular vibrational coupling constants, and 3. initiate magnetic field studies to probe interactions between the spin-density wave condensate (spin-density-wave type) or the lattice dynamics (spin-Peierls-type) and the spin system. At the completion of each set of experiments, the analysis will focus on spectral properties which shed light on the phase transition mechanisms and the changing nature of charge transport through the transition. Energy dissipation mechanisms will receive particular attention. Chemical structure/property considerations, a perspective which comes naturally to chemists, will also play a central role in the analysis. %%% The subject of magnetically driven phase transitions in organic molecular solids has received a great deal of attention in recent years. Despite extensive study, the conditions which govern metal - insulator transitions in low-dimensional solids are a subject of increasing controversy. Therefore, the time has come to re-examine this traditional set of materials with a new set of goals, priorities and tools. The overall goal of this research is to establish a broad program devoted to investigations of magnetically driven phase transitions in low-dimensional solids. Four specific projects are proposed that are of immediate interest to the organic and inorganic materials chemistry community. These projects will allow the Principal investigator and others to evaluate the most promising paths for further investigations in the area of magnetic materials.

摘要 9623221 Musfeldt 这个为期五年的建议是关于获得进一步的信息磁驱动相变在低维有机和无机固体和扩大材料化学课程在纽约的州立大学。在一般情况下，低温光谱响应的几个原型化合物在外部磁场将进行调查。这类化合物具有自旋密度波和自旋Peierls型相变以及许多其他有趣的物理性质。在每种情况下，主要研究者和研究生将：1。利用低温偏振红外光谱和光学光谱在相变附近完整地表征了这些体系的光学常数，2.评估光学常数和基本材料参数，例如相关参数和电子-分子振动耦合常数，以及3.启动磁场研究，以探测自旋密度波凝聚体（自旋密度波型）或晶格动力学（自旋Peierls型）与自旋系统之间的相互作用。在每组实验完成后，分析将集中在光谱特性上，这些特性揭示了相变机制和通过过渡的电荷传输的变化性质。能量耗散机制将受到特别关注。化学结构/性质的考虑，一个自然的角度来化学家，也将在分析中发挥核心作用。 近年来，有机分子固体中的磁驱动相变受到了广泛的关注。尽管进行了广泛的研究，低维固体中金属-绝缘体相变的条件仍是一个越来越有争议的问题。 因此，现在应该重新审查这套传统材料，制定一套新的目标、优先事项和工具。本研究的总体目标是建立一个广泛的计划，致力于低维固体磁驱动相变的调查。 四个具体的项目，提出了直接感兴趣的有机和无机材料化学界。 这些项目将使首席研究员和其他人能够评估磁性材料领域进一步研究的最有前途的途径。