Swekis Peter, Sukhanov Aleksandr S, Chen Yi-Cheng, Gloskovskii Andrei, Fecher Gerhard H, Panagiotopoulos Ioannis, Sichelschmidt Jörg, Ukleev Victor, Devishvili Anton, Vorobiev Alexei, Inosov Dmytro S, Goennenwein Sebastian T B, Felser Claudia, Markou Anastasios
Max Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, 01187 Dresden, Germany.
Institut für Festkörper- und Materialphysik, Technische Universität Dresden, 01062 Dresden, Germany.
Nanomaterials (Basel). 2021 Jan 19;11(1):251. doi: 10.3390/nano11010251.
Magnetic Weyl semimetals are newly discovered quantum materials with the potential for use in spintronic applications. Of particular interest is the cubic Heusler compound CoMnGa due to its inherent magnetic and topological properties. This work presents the structural, magnetic and electronic properties of magnetron co-sputtered CoMnGa thin films, with thicknesses ranging from 10 to 80 nm. Polarized neutron reflectometry confirmed a uniform magnetization through the films. Hard x-ray photoelectron spectroscopy revealed a high degree of spin polarization and localized (itinerant) character of the Mn (Co ) valence electrons and accompanying magnetic moments. Further, broadband and field orientation-dependent ferromagnetic resonance measurements indicated a relation between the thickness-dependent structural and magnetic properties. The increase of the tensile strain-induced tetragonal distortion in the thinner films was reflected in an increase of the cubic anisotropy term and a decrease of the perpendicular uniaxial term. The lattice distortion led to a reduction of the Gilbert damping parameter and the thickness-dependent film quality affected the inhomogeneous linewidth broadening. These experimental findings will enrich the understanding of the electronic and magnetic properties of magnetic Weyl semimetal thin films.
磁性外尔半金属是新发现的量子材料，具有用于自旋电子学应用的潜力。由于其固有的磁性和拓扑性质，立方休斯勒化合物CoMnGa尤其令人关注。这项工作展示了磁控共溅射CoMnGa薄膜的结构、磁性和电子性质，薄膜厚度在10至80纳米之间。极化中子反射测量证实了薄膜中磁化强度的均匀性。硬X射线光电子能谱揭示了Mn（Co）价电子及其伴随磁矩的高度自旋极化和局域（巡游）特性。此外，宽带和与场取向相关的铁磁共振测量表明了与厚度相关的结构和磁性之间的关系。较薄薄膜中拉伸应变诱导的四方畸变的增加反映在立方各向异性项的增加和垂直单轴项的减小上。晶格畸变导致吉尔伯特阻尼参数减小，且与厚度相关的薄膜质量影响了非均匀线宽展宽。这些实验结果将丰富对磁性外尔半金属薄膜电子和磁性性质的理解。
