Investigation of Ultrafast Demagnetization and Gilbert Damping and their Correlation in Different Ferromagnetic Thin Films Grown Under Identical Conditions
arXiv:2301.12797 · doi:10.1088/1361-6528/acc079
Abstract
Following the demonstration of laser-induced ultrafast demagnetization in ferromagnetic nickel, several theoretical and phenomenological propositions have sought to uncover its underlying physics. In this work we revisit the three temperature model (3TM) and the microscopic three temperature model (M3TM) to perform a comparative analysis of ultrafast demagnetization in 20-nm-thick cobalt, nickel and permalloy thin films measured using an all-optical pump-probe technique. In addition to the ultrafast dynamics at the femtosecond timescales, the nanosecond magnetization precession and damping are recorded at various pump excitation fluences revealing a fluence-dependent enhancement in both the demagnetization times and the damping factors. We confirm that the Curie temperature to magnetic moment ratio of a given system acts as a figure of merit for the demagnetization time, while the demagnetization times and damping factors show an apparent sensitivity to the density of states at the Fermi level for a given system. Further, from numerical simulations of the ultrafast demagnetization based on both the 3TM and the M3TM, we extract the reservoir coupling parameters that best reproduce the experimental data and estimate the value of the spin flip scattering probability for each system. We discuss how the fluence-dependence of inter-reservoir coupling parameters so extracted may reflect a role played by nonthermal electrons in the magnetization dynamics at low laser fluences.
References in corpus (16)
- Efficient metallic spintronic emitters of ultrabroadband terahertz radiation
- Super-Diffusive Spin-Transport as a Mechanism of Ultrafast Demagnetization
- Engineering ultrafast spin currents and terahertz transients by magnetic heterostructures
- All-optical control of ferromagnetic thin films and nanostructures
- Nonequilibrium Magnetization Dynamics of Nickel
- Perspective: Ultrafast magnetism and THz spintronics
- Ultrafast demagnetization of ferromagnetic transition metals: The role of the Coulomb interaction
- Spin-flip processes and ultrafast magnetization dynamics in Co - unifying the microscopic and macroscopic view of femtosecond magnetism
- Single pulse all-optical toggle switching of magnetization without Gd: The example of Mn2RuxGa
- The influence of photon angular momentum on ultrafast spin dynamics in Nickel
- Ultrafast Spin Dynamics in Nickel
- Ultrafast transient response and electron-phonon coupling in the iron-pnictide superconductor Ba(Fe(1-x)Co(x))2As2
- Role of Spin Flips versus Spin Transport in Non Thermal Electrons Excited by Ultrashort Optical Pulses in Transition Metals
- Electron-Magnon Scattering in Magnetic Heterostructures Far Out-of-Equilibrium
- Unifying ultrafast demagnetization and intrinsic Gilbert damping in Co/Ni bilayers with electronic relaxation near the Fermi surface
- Enhancement of ultrafast demagnetization rate and Gilbert damping driven by femtosecond laser-induced spin currents in Fe81Ga19/Ir20Mn80 bilayers