Chumak O M, Pacewicz A, Lynnyk A, Salski B, Yamamoto T, Seki T, Domagala J Z, Głowiński H, Takanashi K, Baczewski L T, Szymczak H, Nabiałek A
Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668, Warsaw, Poland.
Institute of Radioelectronics and Multimedia Technology, Warsaw University of Technology, Nowowiejska 15/19, 00-665, Warsaw, Poland.
Sci Rep. 2021 Apr 7;11(1):7608. doi: 10.1038/s41598-021-87205-y.
CoFeMnSi (CFMS) and CoFeGaGe (CFGG) Heusler alloys are among the most promising thin film materials for spintronic devices due to a high spin polarization, low magnetic damping and giant/tunneling magnetoresistance ratios. Despite numerous investigations of Heusler alloys magnetic properties performed up to now, magnetoelastic effects in these materials remain not fully understood; due to quite rare studies of correlations between magnetoelastic and other magnetic properties, such as magnetic dissipation or magnetic anisotropy. In this research we have investigated epitaxial CFMS and CFGG Heusler alloys thin films of thickness in the range of 15-50 nm. We have determined the magnetoelastic tensor components and magnetic damping parameters as a function of the magnetic layer thickness. Magnetic damping measurements revealed the existence of non-Gilbert dissipation related contributions, including two-magnon scattering and spin pumping phenomena. Magnetoelastic constant B values and the effective magnetic damping parameter α values were found to be in the range of - 6 to 30 × 10 erg/cm and between 1 and 12 × 10, respectively. The values of saturation magnetostriction λ for CFMS Heusler alloy thin films were also obtained using the strain modulated ferromagnetic resonance technique. The correlation between α and B, depending on magnetic layer thickness was determined based on the performed investigations of the above mentioned magnetic properties.
CoFeMnSi（CFMS）和CoFeGaGe（CFGG）赫斯勒合金是自旋电子器件中最有前途的薄膜材料之一，因为它们具有高自旋极化、低磁阻尼以及巨大/隧道磁阻比。尽管到目前为止对赫斯勒合金的磁性能进行了大量研究，但这些材料中的磁弹性效应仍未得到充分理解；这是由于对磁弹性与其他磁性能（如磁耗散或磁各向异性）之间相关性的研究相当罕见。在本研究中，我们研究了厚度在15 - 50纳米范围内的外延CFMS和CFGG赫斯勒合金薄膜。我们确定了磁弹性张量分量和磁阻尼参数作为磁层厚度的函数。磁阻尼测量揭示了与非吉尔伯特耗散相关的贡献的存在，包括双磁子散射和自旋泵浦现象。发现磁弹性常数B值和有效磁阻尼参数α值分别在 - 6至30×10尔格/厘米和1至12×10之间。还使用应变调制铁磁共振技术获得了CFMS赫斯勒合金薄膜的饱和磁致伸缩λ值。基于对上述磁性能的研究，确定了α与B之间取决于磁层厚度的相关性。
