Magnetic exchange coupled heterostructures on spherical nanoparticles

磁性与纳米物体降维的结合所产生的新特性不仅在基础科学中引起了相当大的兴趣，而且在广泛的技术应用中也很容易得到应用。在这个项目中，我们的目标是研究在不同尺寸的SiO2球形颗粒阵列上生长的由软硬组分组成的磁异质结构中的磁耦合现象。该系统是实现交换耦合复合介质的潜在兴趣，这是一种新颖的磁数据存储介质概念。FePt:Cu合金是一种硬磁层。作为软层，我们选择Co/Pt多层堆叠，使其易于调整层的磁性能。磁性纳米结构将通过将硬/软复合材料沉积在自组装的非磁性SiO2球形颗粒阵列上，从而形成磁帽阵列。改变颗粒的大小和沉积层的厚度，可以系统地改变相邻帽之间的静磁和交换耦合，从而直接获得纳米尺度上基本磁相互作用的变化。此外，与在平面基底上生长的薄膜相比，在球形颗粒的曲面上沉积磁性薄膜有望导致磁化反转行为的实质性改变。

Novel properties originating from the combination of magnetism with the reduced dimensionality of nanoobjects are of considerable interest for fundamental science but are also readily used in a wide range of technological applications. In this project, we aim to study the magnetic coupling phenomena in magnetic heterostructures consisting of hard and soft components grown on arrays of SiO2 spherical particles of various sizes. This system is of potential interest to realize an exchange coupled composite media, a novel media concept for magnetic data storage. As a hard magnetic layer, FePt:Cu alloys are considered. As a soft layer we choose Co/Pt multilayer stacks allowing easy adjustment of the magnetic properties of the layer. Magnetic nanostructures will be formed by depositing the hard/soft composite onto self-assembled arrays of nonmagnetic SiO2 spherical particles, thus resulting in arrays of magnetic caps. Varying the size of the particles as well as the thickness of the deposited layers, the magnetostatic and exchange coupling between the neighboring caps can be systematically modified, thus providing direct access to the change of the fundamental magnetic interactions at the nanoscale. Moreover, deposition of magnetic films on curved surfaces of spherical particles is expected to result in a substantial modification of the magnetization reversal behavior compared to the films grown on planar substrates.