Open AccessA Model of Microwave Loss Due to Spin Wave Resonance in Grain-Surface-Layers
Author(s) -
Zhongying Han
Publication year - 1999
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.48.291
Subject(s) - laser linewidth , anisotropy , condensed matter physics , materials science , volume fraction , grain size , spin wave , resonance (particle physics) , surface (topology) , excited state , microwave , impurity , physics , optics , composite material , geometry , quantum mechanics , ferromagnetism , mathematics , laser
The spin wave manifold (spin wave eigenfrequencies) for grain-surface-layers is obtained from the precession equation in consideration of the existence of impurity-induced and stran-induced uniaxial anisotropy field Hs. The top and bottom of the manifold for grain-surface-layers at various applied fields H are illustrated in comparison with the manifold for the grain-interior-region. With the detalled calculation, it is revealed that the off-resonance effective linewidth ΔHeff arises from the spin wave resonance excited in some grain-surface-layers and is propotional to the volume fraction of grain-surface-layers. Thus a lot of previous experiments on ΔHeff vs grain size and porosity can be understood well, and the physical meaning of ΔHeff is clarified.