Spin-caloric phenomena in suspended ferromagnets: from plane film to low-dimensional effects

铁磁体中由热梯度引起的自旋输运现象引起了人们对磁学研究的极大兴趣。在这里，对最近发现的自旋塞贝克效应的基本理解提出了一个巨大的挑战。我们建议研究悬浮的铁磁器件中的热诱导自旋输运现象，即从衬底解耦。这将允许我们创建大的热梯度，并接近考虑一维方法的热和自旋电流的理论模型。我们将修改铁磁体的输运性质，我们将通过例如狭窄的收缩或周期性的孔阵列来对铁磁体进行纳米化。我们将进一步考虑非均匀磁化模式和畴壁。通过这些方法，我们将解决声子（晶格振动）、磁振子（集体自旋激发）、电子和自旋电流在多大程度上相关并有助于热致电信号的开放问题。

Spin transport phenomena induced by thermal gradients in a ferromagnet have generated a large interest in magnetism research. Here, the fundamental understanding of the recently discovered spin Seebeck effect presents a great challenge. We propose to investigate heat-induced spin transport phenomena in ferromagnetic devices which are suspended, i.e., decoupled from the substrate. This will allow us to create large thermal gradients and come close to theoretical models considering a onedimensional approach for heat and spin-current flow. We will modify the transport properties in that we nanopattern the ferromagnet by, e.g., narrow constrictions or periodic arrays of holes. We will further consider inhomogeneous magnetization patterns and domain walls. By these means we will address the open question to which degree phonons (lattice vibrations), magnons (collective spin excitations), electron and spin currents are relevant and contribute to the heat-induced electrical signals.