Out-of-plane angular dependence of ferromagnetic resonance spectra was measured in sputtered Co/Pt multilayers and analyzed with the Landau-Lifshitz-Gilbert equation. The effective demagnetizing field 4πMeff is found...Out-of-plane angular dependence of ferromagnetic resonance spectra was measured in sputtered Co/Pt multilayers and analyzed with the Landau-Lifshitz-Gilbert equation. The effective demagnetizing field 4πMeff is found to increase with decreasing tPt and decreasing 1/tco, which can be considered as a result of interplay between the interlayer coupling and a lowdimensional effect. The g factor increases with increasing tpt and decreasing tCo, indicating contribution of spin-polarization of Pt atoms and additional contribution of orbital moment of Co atoms. The in-plane resonance line-width increases with decreasing too and increases with increasing tPt.展开更多
In dynamic laser light scattering (LLS), for a given plydisperse sample, a line-width distribution G(Γ) or the translational diffusion coefficient distributionG(D) can be obtained from the measured time correlation f...In dynamic laser light scattering (LLS), for a given plydisperse sample, a line-width distribution G(Γ) or the translational diffusion coefficient distributionG(D) can be obtained from the measured time correlation function. For rigid colloid particles,G(Γ) can be directly related to the hydrodynamic size distribution. However, for flexible polymer chains, G (Γ) depends not only on the chain length distribution, but also on the relaxation of the chain conformation; that is, even for a monodisperse polymer sample there still exists a chain conformation distribution. If the time scale of the chain conformation relaxation is comparable to that of the translational diffusion, such as in the case of a very long polymer chain, the conformation relaxation might lead to an additional broadening in G(Γ). This ‘conformation broadening’ has been directly observed for the first time by comparing twoG(Γ)s obtained from a ply(N-iso-propyl-acrylamide) solution at ~25°C: and ~ 32°C at which the solution is thermodynamically stable, where the fact is utilized that the PNIPAM chain can change from an extended and flexible coil at ~25°C into a highly collapsed and compact globule at ~ 32°C at which pint the polymer chain conformation distribution has diminished.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant Nos.10504019, 10574087）, and the Shanghai Leading Academic Disciplines Program （Grant No.T0104）
文摘Out-of-plane angular dependence of ferromagnetic resonance spectra was measured in sputtered Co/Pt multilayers and analyzed with the Landau-Lifshitz-Gilbert equation. The effective demagnetizing field 4πMeff is found to increase with decreasing tPt and decreasing 1/tco, which can be considered as a result of interplay between the interlayer coupling and a lowdimensional effect. The g factor increases with increasing tpt and decreasing tCo, indicating contribution of spin-polarization of Pt atoms and additional contribution of orbital moment of Co atoms. The in-plane resonance line-width increases with decreasing too and increases with increasing tPt.
基金Supported by the Climbing Project of the Chinese National Basic Project--Macromolecule Condensed State, the Research Grants Council (RGC) of Hong Kong Government Earmarked Grants 1997/98 (CUHK4181/97P, 2160082, RGC/96-97/03)the National Distinguish
文摘In dynamic laser light scattering (LLS), for a given plydisperse sample, a line-width distribution G(Γ) or the translational diffusion coefficient distributionG(D) can be obtained from the measured time correlation function. For rigid colloid particles,G(Γ) can be directly related to the hydrodynamic size distribution. However, for flexible polymer chains, G (Γ) depends not only on the chain length distribution, but also on the relaxation of the chain conformation; that is, even for a monodisperse polymer sample there still exists a chain conformation distribution. If the time scale of the chain conformation relaxation is comparable to that of the translational diffusion, such as in the case of a very long polymer chain, the conformation relaxation might lead to an additional broadening in G(Γ). This ‘conformation broadening’ has been directly observed for the first time by comparing twoG(Γ)s obtained from a ply(N-iso-propyl-acrylamide) solution at ~25°C: and ~ 32°C at which the solution is thermodynamically stable, where the fact is utilized that the PNIPAM chain can change from an extended and flexible coil at ~25°C into a highly collapsed and compact globule at ~ 32°C at which pint the polymer chain conformation distribution has diminished.
