Fakhrul Takian, Khurana Bharat, Lee Byung Hun, Huang Siying, Nembach Hans T, Beach Geoffrey S D, Ross Caroline A
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Associate, Physical Measurement Laboratory, National Institute of Standards and Technology, Boulder, Colorado 80305, United States.
ACS Appl Mater Interfaces. 2024 Jan 17;16(2):2489-2496. doi: 10.1021/acsami.3c14706. Epub 2024 Jan 5.
Thin films of ferrimagnetic iron garnets can exhibit useful magnetic properties, including perpendicular magnetic anisotropy (PMA) and high domain wall velocities. In particular, bismuth-substituted yttrium iron garnet (BiYIG) films grown on garnet substrates have a low Gilbert damping but zero Dzyaloshinskii-Moriya interaction (DMI), whereas thulium iron garnet (TmIG) films have higher damping but a nonzero DMI. We report the damping and DMI of thulium-substituted BiYIG (BiYTmIG) and TmIG|BiYIG bilayer thin films deposited on (111) substituted gadolinium gallium garnet and neodymium gallium garnet (NGG) substrates. The films are epitaxial and exhibit PMA. BiYIG|TmIG bilayers have a damping value that is an order of magnitude lower than that of TmIG, and BiYIG|TmIG|NGG have DMI of 0.0145 ± 0.0011 mJ/m, similar to that of TmIG|NGG. The bilayer therefore provides a combination of DMI and moderate damping, useful for the development of high-speed spin orbit torque-driven devices.
亚铁磁性铁石榴石薄膜可展现出有用的磁性能，包括垂直磁各向异性（PMA）和高畴壁速度。特别是，在石榴石衬底上生长的铋取代钇铁石榴石（BiYIG）薄膜具有低吉尔伯特阻尼但零Dzyaloshinskii-Moriya相互作用（DMI），而铥铁石榴石（TmIG）薄膜具有较高的阻尼但非零DMI。我们报道了沉积在（111）取代钆镓石榴石和钕镓石榴石（NGG）衬底上的铥取代BiYIG（BiYTmIG）和TmIG|BiYIG双层薄膜的阻尼和DMI。这些薄膜是外延生长的且展现出PMA。BiYIG|TmIG双层薄膜的阻尼值比TmIG低一个数量级，并且BiYIG|TmIG|NGG的DMI为0.0145±0.0011 mJ/m，与TmIG|NGG的相似。因此，该双层薄膜提供了DMI和适度阻尼的组合，对高速自旋轨道扭矩驱动器件的开发很有用。
