Magnetic properties of large paramagnetic polyoxometalates: magnetochemical and magnetic resonance spectroscopy

在其较高的氧化态下，亚族V和VI的元素有形成多核阴离子金属氧团簇的趋势，其拓扑结构和电子多样性是无与伦比的。这些团簇可以作为研究纳米结构系统的发展和性质的理想对象。在这方面，我们最感兴趣的是我们最近成功隔离的巨大但离散的集群。在这些纳米结构颗粒中可能观察到的一些特性是基于目前仅从扩展固体中已知的效应。在此背景下，我们打算详细研究这些团簇的自旋组织，包括相关的磁性和磁有序。使用一种新的高频方法（世界范围内只有三个组可以使用）直接确定能级，交换和超精细相互作用以及晶体场，以及它们如何受环境，缺陷等的影响。

In their higher oxidation state the elements of the subgroups V and VI have the tendency to form polynuclear, anionic metal-oxygen clusters which are unsurpassed in their topological and electronic diversity. These clusters may serve as ideal objects to study the development and the properties of nanostructured systems. Of paramount interest in this regard are the giant but discrete clusters we recently succeeded to isolate. Some properties which may be observed in these nanostructured particles are based on effects which are at present only known from extended solids. In this context we intend to investigate the spin organization of those clusters in detail, including the related magnetism and magnetic ordering. Using a new high-frequency method (worldwide accessible to only three groups) the energy levels, the exchange and hyperfine interactions, and the crystal fields shall be directly determined, and how they are influenced by the environment, defects, etc.