Ordered arrangements of selective-area grown MnAs clusters as components for planar magneto-electronic devices: Experiment and theory

由嵌入在基质材料中或排列在表面上的纳米团簇组成的颗粒状杂化结构的性质可以广泛地调节。与单相材料相比，复合材料混杂材料具有更大的自由度，因此具有可调性。然而，这种颗粒状杂化材料的技术应用主要局限于宏观器件，即团簇之间的平均距离远远小于特征器件尺寸，因为大多数生长方法只产生随机排列的团簇。在不同衬底上选择性区域金属-有机气相生长MNAs团簇的最新进展使人们能够精确地调节铁磁性MNAs纳米团簇的位置、大小和形状，从而获得几个纳米团簇的有序排列，这可能是新型平面磁电子器件的起点。在这里，我们想要研究单个MNAs团簇以及耦合团簇排列的磁性和磁输运性质。可以在生长过程期间或之后通过修改布置的簇之间的界面，以受控的方式调节耦合的簇布置的属性。磁和磁输运的结果将被关联，并与从头计算进行比较。在这些结果的基础上，将提出新的器件结构并进行初步测试。

The properties of granular hybrid structures, consisting of nanoclusters embedded in a matrix material or arranged on surfaces can be widely tuned. The tuneability arises from the larger number of degrees of freedom in a composite hybrid compared to a single-phase material. However, the technological application of such granular hybrids has been mainly restricted to macroscopic devices, i.e. where the mean distance between clusters is much smaller than the characteristic device size, as most growth methods yield random arrangements of clusters only. Recent progress in selective-area metal-organic vapor phase growth of MnAs clusters on different substrates allows one to accurately tune the position, the size and the shape of ferromagnetic MnAs nanoclusters and, thus, to obtain ordered arrangements of a few nanoclusters which may serve as the starting point for novel planar magnetoelectronic devices. Here, we want to study the magnetic and the magneto-transport properties of individual MnAs clusters as well as of coupled cluster arrangements. The properties of the coupled cluster arrangements can be tuned in a controlled way during the growth process or afterwards by modifying the interface between clusters of the arrangement. Magnetic and magnetotransport results will be correlated and compared with ab initio calculations. On the basis of these results novel device structures will be proposed and preliminary tests will be performed.