Novel magnetic excitations in complex electronic materials

该项目涉及一类磁性材料的研究，这些材料显示出惊人的物理特性，这些特性可能在未来的电子应用中有用，例如数据存储。例如，对某些锰氧化物化合物施加磁场可以将材料的状态从绝缘体改变为金属。这种现象和最近发现的其他现象可以追溯到材料中电子的集体行为：电子会自我组织，这样一个小的外部刺激就能产生一个大的响应。关于磁性材料中集体现象背后的微观机制，而解决这些问题最直接的方法之一就是用中子能谱研究原子尺度的动力学。在这个项目中，我们将开发新的技术和仪器的飞行时间中子散射与位置敏感探测器在ISIS设施。这一提议的时间安排与MERLIN和LET光谱仪的完成一致，后者位于新的ISIS-TS 2设施上。这些仪器测量完整自旋激发光谱图的能力将使目前无法完成的实验成为可能，因此，在接下来的几年里，有一个令人兴奋的机会在该领域取得重大进展。该奖项将为项目学生提供实验技术的全面基础，以研究相互作用-电子现象，并将培养学生成为中子散射设施的下一代用户所需的必要技能和知识。

This project is concerned with the investigation of a class of magnetic materials which show dramatic physical properties that could be useful in future electronic applications such as data storage. For instance, the application of a magnetic field to some manganese oxide compounds can change the state of the material from an insulator to a metal. This and other recently discovered phenomena can be traced back to collective behaviour of the electrons in the material: the electrons organise themselves so that a small external stimulus can produce a large response.There are still many unanswered questions about the microscopic mechanisms behind collective phenomena in magnetic materials, and one of the most direct ways of tackling these problems is to investigate the atomic-scale dynamics by neutron spectroscopy. In this project we will exploit new techniques and instrumentation for time-of-flight neutron scattering with position-sensitive detectors at the ISIS Facility. This proposal is timed to coincide with the completion of the MERLIN and LET spectrometers, the latter on the new ISIS-TS2 facility. The ability of these instruments to measure complete maps of spin excitation spectra will make possible experiments that cannot be done at present, so there is an exciting opportunity in the next few years to make significant advances in the field.The award will provide a project student with a thorough grounding in experimental techniques to investigate interacting-electron phenomena and will train the student in the necessary skills and knowledge required to become a next generation user of neutron scattering facilities.