title: Selective Tuning of Gilbert Damping in Spin-Valve Trilayer by Insertion of Rare-Earth Nanolayers.
abstract: Selective tuning of the Gilbert damping constant, α, in a NiFe/Cu/FeCo spin-valve trilayer has been achieved by inserting different rare-earth nanolayers adjacent to the ferromagnetic layers. Frequency dependent analysis of the ferromagnetic resonances shows that the initially small magnitude of α in the NiFe and FeCo layers is improved by Tb and Gd insertions to various amounts. Using the element-specific technique of X-ray magnetic circular dichroism, we find that the observed increase in α can be attributed primarily to the orbital moment enhancement of Ni and Co, rather than that of Fe. The amplitude of the enhancement depends on the specific rare-earth element, as well as on the lattice and electronic band structure of the transition metals. Our results demonstrate an effective way for individual control of the magnetization dynamics in the different layers of the spin-valve sandwich structures, which will be important for practical applications in high-frequency spintronic devices.
authors.affiliation: †Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Zhang
authors.affiliation: †Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: §Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.|∥NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.
authors.forename: Ping Kwan Johnny
authors.initials: PK
authors.lastname: Wong
authors.affiliation: †Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Honglei
authors.initials: H
authors.lastname: Yuan
authors.affiliation: †Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Jiang
authors.affiliation: ⊥Magnetic Spectroscopy Group, Diamond Light Source, Didcot OX11 0DE, United Kingdom.
authors.forename: Gerrit
authors.initials: G
authors.lastname: van der Laan
authors.affiliation: †Department of Physics, Southeast University, Nanjing 211189, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Zhai
authors.forename: Zuhong
authors.initials: Z
authors.lastname: Lu
keywords: FMR; Gilbert damping; XMCD; ferromagnet/normal-metal/ferromagnet trilayer; orbital moment; rare-earths; spintronics; spin−orbit coupling