Cluster Superlattice Membranes

团簇超晶格膜是一种新型的二维材料。这种膜由位于2D六边形阵列中的簇组成，晶格常数为2-4 nm。团簇的晶格具有原子精度，但比原子尺度更大，因此是超晶格。簇超晶格夹在原子厚度的单晶2D层和nm厚度的嵌入基质之间，使得基质与簇和2D层一起形成可以具有mm横向延伸的机械稳定的片。其机械完整性使得能够从主体基底转移到另一基底或其用作独立膜。团簇的大小可以从单个原子限制到大约400个原子。使用这些新的2D材料进行拟议研究的目标有三个方面。首先，目标是开发这种膜的制造，以获得大量多样性的材料。这将包括实现开放膜，使得簇可以与环境相互作用，例如用于电催化中的应用。团簇的后生长以及开放膜与新金属膜的结合将拓宽其在纳米磁学研究中的应用潜力。以氧化物为主体材料的膜的实现将获得光学和电学传输特性，并能够在高温下进行多相催化。其次，将彻底分析膜的性能，即它们在恶劣环境中的不渗透性和稳定性。特别感兴趣的是它们的高温行为。在这里，优异的抗烧结性预测，包括抑制Smoluchowski熟化和逆奥斯特瓦尔德熟化。第三，为了展示这些团簇超晶格膜在基础研究中的潜力，我们将构建磁性粒子的膜并分析它们的磁性相互作用。容纳团簇的膜的空腔将被用作小颗粒相变的反应器，否则这是不可能的。碳和氧化物基质中的开放贵金属超晶格膜将在液体和气体环境中作为催化剂进行测试。

Cluster superlattice membranes are a new type of two dimensional (2D) material. Such a membrane consists of clusters positioned in a 2D hexagonal array with a lattice constant of 2-4 nm. The lattice of clusters is of atomic precision, but of larger than atomic scale, and thus a superlattice. The cluster superlattice is sandwiched between a single crystal 2D layer of atomic thickness and an embedding matrix of nm thickness, such that the matrix together with the clusters and the 2D layer forms a mechanically stable sheet which can have mm lateral extension. Its mechanical integrity enables the transfer from a host substrate to another substrate or its use as a freestanding membrane. The clusters are tunable in size from the single atom limit up to about 400 atoms. The objective of the proposed research with these new 2D materials is threefold. First, it is the goal to develop the making of such membranes in order to obtain materials in a large diversity. This will include the realization open membranes, such that the clusters can interact with the environment, e.g. for applications in electrocatalysis. Post growth of clusters and combining open membranes with new metallic films will broaden their application potential for nanomagnetic investigations. Realization of membranes with oxides as a host material will give access to optical as well as electrical transport properties, and enable heterogeneous catalysis at elevated temperatures. Second, the membrane properties will be thoroughly analyzed, namely their proposed impermeability and stability in harsh environments. Of specific interest is their high temperature behavior. Here, excellent resistance against sintering is predicted, including suppression of Smoluchowski ripening and inverse Ostwald ripening. Third, to demonstrate the potential of these cluster superlattice membrane in fundamental research, we will construct membranes of magnetic particles and analyze their magnetic interaction. The cavities of the membranes that host the clusters will be used as reactors for phase transformations in small particles that otherwise would not be possible. Open noble metal superlattice membranes in carbon and oxide matrix will be tested as catalysts in liquid and gaseous environments.