Electronic and magnetic properties in monolayer/substrate interfaces of metallofullerene single molecule magnet Tb2@C79N featuring single-electron Tb-Tb bond

在分子水平上实现磁性在技术上是非常有吸引力的，因为它保证了可能的存储密度的急剧增加，并提供了许多自旋电子学应用。单分子磁铁（SMM）的潜在纳米器件实现的先决条件是其在散装粉末或晶体样品中表现出的磁性双稳定性应该保留在衬底上，衬底将作为器件的电极。由于难以获得结构清晰的SMM层，以及金属衬底对SMM性能的影响日益恶化，这些技术的实际实现受到阻碍。将镧系元素封装在化学和热稳定的碳笼中，可以显著改善导电衬底上的SMM性能，这是在分子器件中实现SMM所必需的。Tb2deltaC79N氮杂富勒烯优异的SMM性能，加上富勒烯笼的保护作用，使该分子成为改善表面SMM性能的完美候选分子。在这个项目中，我们将全面研究Tb2deltaC79N单层在导电衬底界面上的磁性。通过扫描隧道显微镜对Tb2deltaC79N单层膜的形貌进行研究，优化Tb2deltaC79N单层膜在不同衬底上的气相沉积工艺。然后用x射线磁圆二色性分析单层膜的磁性。低温STM技术将用于分子分辨率分析富勒烯/衬底界面上的电子特性。本研究将为emf - smm在分子自旋电子学和量子信息处理中的潜在应用提供背景。

Realization of magnetism on a molecular level is technologically very attractive since it promises a dramatic increase of possible storage density and offers a number of spintronics applications. A prerequisite for potential nanodevice implementation of a given single molecule magnet (SMM) is that its magnetic bistability demonstrated in bulk powder or crystal sample should be preserved on a substrate, which will serve as an electrode of a device. The practical realization of such technologies are hampered by difficulties in the obtaining of the well-structurally defined layers of SMMs, and deteriorating effect of metallic substrates on the SMM properties. Encapsulation of lanthanide species within chemically and thermally stable carbon cages opens the possibility for a dramatic improvement of the SMM performance on conducting substrates, which is required for implementation of SMMs in molecular devices. Excellent SMM properties of Tb2deltaC79N azafullerene combined with the protective role of the fullerene cage make this molecule a perfect candidate for improved on-surface SMM performance. In this project we will perform comprehensive studies of the magnetism of Tb2deltaC79N monolayers on the interface with conducting substrates. Vapor deposition of Tb2deltaC79N monolayers on various substrates will be optimized first following the scanning tunneling microscopy study of the layer morphology. Magnetic properties of the monolayers will be then analyzed by X-ray magnetic circular dichroism. Low-temperature STM technique will be used to analyze electronic properties on the fullerene/substrate interface with molecular resolution. This study will form a background for the potential use of EMF-SMMs in molecular spintronics and quantum information processing.