Optimisation of Co2MnSi thin films and ANE

Characterisation of Co2MnSi thin films and corresponding ANE measurements. Origin dataset associated with article: Anomalous Nernst Effect in Co2MnSi Thin Films AbstractSeparation of the anomalous Nernst and spin Seebeck voltages in bilayer devices is often problematic when both layers are metallic, and the anomalous Nernst effect becomes non-negligible. Co2MnSi, a strong candidate for the spin generator in spin Seebeck devices, is a predicted half-metal with 100% spin polarisation at the Fermi energy, however, typically B2 or L21 order is needed to achieve this. We demonstrate the optimisation of thin film growth of Co2MnSi on glass, where choice of deposition and annealing temperature can promote various ordered states. The contribution from the anomalous Nernst Effect (ANE) is then investigated to inform future measurements of the spin Seebeck. A maximum ANE coefficient of 0.662μV/K is found for an A2 disordered polycrystalline Co2MnSi film. This value is comparable to ordered Heusler thin films deposited on to single crystal substrates but obtained at a far lower fabrication temperature and material cost.

Co₂MnSi薄膜的表征及其反常能斯特效应（Anomalous Nernst Effect, ANE）测量。本数据集与论文《Co₂MnSi薄膜中的反常能斯特效应》相关。摘要：在双层器件中，当两层均为金属且反常能斯特效应不可忽略时，分离反常能斯特电压与自旋塞贝克电压（spin Seebeck voltage）通常存在困难。Co₂MnSi作为自旋塞贝克器件中自旋发生器的有力候选材料，是理论预测的在费米能级（Fermi energy）处具备100%自旋极化率的半金属（half-metal），但通常需要形成B2型或L21型有序结构才能实现该特性。本研究实现了玻璃衬底上Co₂MnSi薄膜生长的优化，通过调控沉积温度与退火温度可促进形成不同的有序态。随后对反常能斯特效应的贡献展开研究，以指导后续自旋塞贝克效应的测量。针对A2型无序多晶Co₂MnSi薄膜，测得其最大反常能斯特系数为0.662 μV/K。该数值与沉积在单晶衬底（single crystal substrates）上的有序赫斯勒薄膜（Heusler thin films）相当，但制备所需温度与材料成本均显著更低。