基体表面笼形镧系金属原子掺杂硅团簇的结构、电子和磁性质研究

Silicon clusters, with unique cage structure and superatomic character, have shown great potential applications in future spintronic devices. However, due to the existence of dangling bonds, the caged silicon clusters are generally unstable. The lanthanide dopants can not only stabilize the silicon cage, but also bring appealing magnetic properties due to their unique electronic structures. To promote the applications of silicon clusters in nano-assembly materials, it is therefore of great importance to deposit these caged clusters on substrate and investigate their structural, electronic and magnetic properties. In this project, the deposited lanthanide doped silicon clusters, SinLn (n=16、20; Ln=Pr、Eu、Gd、Ho、Lu), will be investigated by Raman spectroscopy, X ray and ultraviolet photoelectron spectroscopy, and X-ray magnetic circular dichroism, in combination with density functional theory calculations, respectively. It will allow us to clarify and deepen the understanding of the effects of the interactions between dopant-silicon, cluster-substrate and cluster-cluster etc. to the structural, electronic and magnetic properties of the deposited clusters, as well as reveal the magnetic exchange couplings. The success of the present project will eventually promote the application of lanthanide doped silicon clusters as building blocks in constructing spintronic nano-assembly devices.

具有超原子特性的笼形结构硅团簇可以作为未来自旋电子纳米器件的构建基元。然而笼形硅团簇存在悬空键，具有化学不稳定性，镧系金属原子掺杂不仅有助于硅团簇形成稳定的内嵌笼形结构，同时由于其特殊的电子结构，能带来优异的磁性能。因此将这些具有笼形结构的掺杂硅团簇沉积到基体表面，并系统研究其结构、电子和磁性性质，具有重要意义。本项目拟以SinLn(n=16、20; Ln=Pr、Eu、Gd、Ho、Lu)团簇为研究对象，通过拉曼光谱表征团簇结构、利用X射线和紫外光电子能谱研究其电子结构、采用X射线磁圆二色谱测量其磁性质，结合理论计算系统深入研究镧系金属掺杂硅团簇在基体表面的稳定结构、电子和磁性质，阐明掺杂原子−硅、团簇−基体、团簇−团簇间等相互作用对团簇结构、电子和磁性质的影响机理，揭示团簇的磁耦合机制，从而推动镧系金属掺杂硅团簇作为构建基元在磁性纳米组装材料中的应用。

具有特定尺寸的超小团簇因为其量子尺寸效应，常常具有不同块体材料的物理化学性质。本项研究通过具有质量选择功能的磁控溅射团簇设备，将特定尺寸的团簇沉积在基体上，结合先进表征手段及DFT理论计算，系统研究了团簇在基体表面的电子结构、磁性能和催化性能等。具体内容如下：结合DFT理论计算系统阐述了硅-镧系金属原子间电子相互作用、硅团簇-富勒烯电子相互作用等对镧系金属原子，尤其是磁矩的影响机理；结合实验与理论计算，对沉积金属团簇的电催化性能进行了系统研究，揭示了团簇量子效应、团簇-载体间相互作用等对其催化性能的影响机制。本项研究将加深人们对团簇在基体表面物理化学性质的认识。