Materials World Network: A Study of Spin Dynamics in Fe/CoO/MgO(001) and Fe/NiO/MgO(001) Using Time-Resolved and Element-Specific XMCD and XMLD

技术摘要：材料世界网络合作将开发一个研究计划，在劳伦斯伯克利国家实验室的高级光源(ALS)上对磁性纳米结构中的自旋动力学进行时间分辨和特定于元素的测量。铁磁/反铁磁(FM/AFM)Py/CoO和Py/NiO双层薄膜将通过分子束外延(MBE)在MgO(001)衬底上生长，并通过共面波导样品设计向样品提供2或4 GHz的微波，以产生Py层的铁磁共振(FMR)。通过将微波源与ALS加速器频率同步，研究小组将对Py自旋动力学进行时间分辨和元素特定的X射线磁圆二色谱(XMCD)，并对CoO或NiO自旋动力学进行X射线磁线性二色性(XMLD)。这项研究将涉及美国加州大学伯克利分校和埃克塞特大学之间的密切合作。以及美国ALS公司和英国钻石资源公司之间的关键技术信息。非技术摘要：随着磁性器件的运行速度越来越快，自旋动力学在纳米结构中变得越来越重要。特别是，纳秒或GHz范围设定了一个关键的时间尺度，超过这个时间尺度，自旋过程开始主导自旋转换中的磁畴壁运动。这一材料世界网络合作研究计划将发展对FM/AFM纳米结构中GHz范围内的自旋动力学的基本理解。为了实现这一目标，美国、英国和同步加速器的专家需要共同努力。研究结果将有助于理解在重要的ns时间范围内的自旋动力学，为未来的自旋电子学器件提供指导。研究生将通过交流计划接受现代实验技术前沿的培训，这对他们未来在学术、工业和政府工作中的职业生涯至关重要。该项目由凝聚态物理计划和材料研究部特别计划办公室支持。

Technical Abstract: This Materials World Network collaboration will develop a research program to perform time-resolved and element-specific measurement on spin dynamics in magnetic nanostructures at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Ferromagnetic/Antiferromagnetic (FM/AFM) Py/CoO and Py/NiO bilayers will be grown on MgO(001) substrate by Molecular Beam Epitaxy (MBE) and 2 or 4GHz microwaves will be delivered to the sample through coplanar waveguide sample design to generate ferromagnetic resonance (FMR) of the Py layer. By synchronizing the microwave source with the ALS accelerator frequency, the research team will perform time-resolved and element-specific X-ray Magnetic Circular Dichroism (XMCD) on the Py spin dynamics and X-ray Magnetic Linear Dichroism (XMLD) on the CoO or NiO spin dynamics. The research will involve a close collaboration by exchanging students between UC-Berkeley at US and Exeter Univ. at UK, as well as critical technical information between ALS in US and Diamond Source in UK. Non-Technical Abstract: As magnetic devices perform faster and faster, spin dynamics becomes more and more important in nanostructures. In particular, nanosecond or GHz range sets a critical time scale beyond which spin procession starts domination domain wall motion in spin switching. This Materials World Network collaborative research program will develop a basic understanding of the spin dynamics right in the GHz range in FM/AFM nanostructures. In order to achieve this goal, collaborative effort is needed among US, UK, and Synchrotron expertise. Results of the research will lead to an understanding of the spin dynamics in the important ns time range to provide guidance for future spintronics devices. Graduate students will receive training at the cutting edge of modern experimental techniques through exchange program, which is crucial for their future careers in academic, industrial, and government jobs.This project is supported by the Condensed Matter Physics Program and the Office of Special Programs in the Division of Materials Research.