Light-Induced Magnetic Switching as a Trigger for Phase Transitions in Molecular Materials

光感磁开关作为分子材料相变的触发器

• 批准号: 1464955
• 负责人: Mykhailo Shatruk
• 金额: $ 45.1万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-01 至 2019-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1464955&HistoricalAwards=false
• 关键词: Light; Induced; Magnetic; Switching; Trigger

With this award, the Chemical Structure, Dynamics & Mechanisms B Program of the Chemistry Division is funding a collaborative research team led by Professors Mykhailo Shatruk and Nar S. Dalal of the Department of Chemistry and Biochemistry at Florida State University to investigate photoresponsive molecules that can translate the action of heat, pressure, or light irradiation into substantial changes into changes in the magnetic and structural properties of materials. The successful implementation of this design principle could potentially lead to new ferroelectrics and conductors that could be actuated by the action of light. Leveraging the expertise of the Shatruk and Dalal groups in the synthesis and characterization of magnetic and photomagnetic materials, ferroelectric materials, and organic conductors, the team aims to create novel multifunctional materials that can be employed in electronic devices or light-activated switches. The project will actively involve graduate and undergraduate students in laboratory research, including students from groups underrepresented in physical sciences. The research team plans to continue their Undergraduate Summer Schools on Magnetism, first organized in Summers of 2012 and 2014, with the next school scheduled for Summer 2016.This project targets the synthesis and characterization of photoresponsive molecules capable of translating temperature-, pressure-, or light-induced changes in the magnetic state of the system into substantial structural changes, which consequently would trigger another type of phase transition in the material. The Shatruk/Dalal team will explore approaches to couple the photoinduced magnetic bistability at the molecular level to long-range metal-insulator transitions and ferroic orderings (magnetic or electric) in molecule-based materials. In particular, the team will study Fe(II) complexes with spin crossover (SCO) behavior, which stems from the temperature or light-induced transition between diamagnetic low-spin (LS) and paramagnetic high-spin (HS) states of the Fe(II) ion. The photoinduced LS to HS transitions will be invoked in order to achieve properties such as ferroelectricity and conductivity via photoexcitation. Materials in which SCO coexists with conductivity will provide a platform to test the effects of concerted atomic displacements associated with SCO on the conductivity of the organic substructure, with the potential to achieve photoinduced superconductivity via chemical compression. Another thrust aims to explore photoinduced magnetic switching, akin to SCO, in metal-free organic systems, where the change in the magnetic state is due to interconversions between paramagnetic radicals and diamagnetic dimers of radicals. The study of such metal-free systems could open up a new area in the molecular magnetism field that would parallel the studies currently performed on transition metal complexes.

有了这个奖项，化学结构，动态和机制B计划为佛罗里达州立大学化学和生物化学系教授和Nar S. Dalal领导的一个合作研究团队提供了资金，以调查光的分子调查可以将热量和光照射变为实质性变化和实质性变化的效率变化。 该设计原理的成功实施可能会导致新的铁电和导体，这可能会通过光的作用来驱动。该团队利用Shatruk和Dalal基团在磁和光磁材料，铁电材料以及有机导体的合成和表征方面的专业知识，旨在创建可用于电子设备或光激活开关的新型多功能材料。该项目将积极参与研究生和本科生的实验室研究，包括来自体育科学领域不足的小组的学生。研究小组计划继续在2012年和2014年夏季首次组织磁性的本科暑期学校，下一所学校安排在2016年夏季。该项目的目标是将温度，压力，压力，压力或光线诱导的系统变化变化变化的材料变化的光反应分子的综合和表征，这将构成实质性的变化。 Shatruk/Dalal团队将探索在分子水平上将光诱导的磁性双重性与远程金属绝缘体的跃迁和基于分子的材料中的铁反订购（磁或电动）的方法。特别是，团队将研究具有自旋跨界（SCO）行为的Fe（II）复合物，这源于Fe（II）离子的Dimagnetic低自旋（LS）和顺磁性高旋转（LS）和顺磁性高旋转状态（II）离子之间的温度或光诱导的过渡。为了通过光激发来实现诸如铁电性和电导率之类的属性，将调用光诱导的LS到HS转换。 SCO共存具有电导率的材料将提供一个平台，以测试与SCO相关的协同原子位移对有机子结构电导率的影响，并有可能通过化学压缩实现光诱导的超导性。 另一个推力旨在探索无金属有机系统中的光诱导的磁开关，类似于SCO，在该系统中，磁性状态的变化是由于顺磁性自由基与自由基的二聚体之间的相互转换所致。对这种无金属系统的研究可以在分子磁场领域开放一个新区域，该区域将与当前在过渡金属复合物上进行的研究平行。