國立臺灣大學物理系所Huang, Huei-LiHuei-LiHuang2006-09-272018-06-282006-09-272018-06-281997-08http://ntur.lib.ntu.edu.tw//handle/246246/20060927120000179881The coordinate and transverse field dependence of the domain wall (DW) magnetization structure across the wall proper and the corresponding dependence of the effective DW width of both the polar and azimuthal angle distribution has been investigated. The effective width of the azimuthal angle distribution is found to vary with the orientation and strength of the transverse field and is much broader than the conventional wall width due to the polar angle distribution. On dynamics, the analysis of the DW motion in the presence of the transverse field normal to the anisotropy axis taking into account the nonconservation of the magnetization modulus has uncovered two types of the magnetization damping parameters. One is that of the Landau-Lifihitz damping constant, XPMR, which characterizes the homogeneous magnetization manifested in the ferromagnetic resonance line width. The other, X,, is associated with the inhomogeneous magnetization such as the DW which gives rise to an extra viscous damping. Numerically, X, can be of the same order or several factors greater than XPMR. Our formulation establishes the existence of two distinctly different damping processes associated with a ferromagnet sample which the Landau-Lifshitz-Gilbert equation fails inherently.application/pdf312860 bytesapplication/pdfzh-TWjournal articlehttp://ntur.lib.ntu.edu.tw/bitstream/246246/20060927120000179881/1/0480.pdf