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

这个为期五年的提案是关于在纽约州立大学的低维有机和无机固体和膨胀材料化学课程中获得关于磁驱动相变的进一步信息。一般来说，将研究几种原型化合物在外加磁场中的低温光谱响应。众所周知，这些化合物显示出自旋密度波和自旋佩尔斯型相变，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相变附近的光谱完全表征了这些系统的光学常数，2。2 .评估光学常数和基本材料参数，如相关参数和电子-分子振动耦合常数；发起磁场研究，探索自旋密度波凝聚体（自旋密度波型）或晶格动力学（自旋-佩尔斯型）与自旋系统之间的相互作用。在每组实验完成后，分析将重点放在光谱特性上，这些特性揭示了相变机制和电荷在相变过程中输运的变化性质。能量耗散机制将受到特别关注。化学结构/性质的考虑，这是化学家自然会想到的观点，也将在分析中发挥核心作用。近年来，有机分子固体中磁驱动相变的研究受到了广泛的关注。尽管进行了广泛的研究，但控制低维固体中金属绝缘体转变的条件是一个越来越有争议的主题。因此，现在是时候用一套新的目标、优先事项和工具来重新审视这些传统的材料了。这项研究的总体目标是建立一个广泛的计划，致力于研究低维固体中磁驱动的相变。提出了有机和无机材料化学社区直接感兴趣的四个具体项目。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。

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.