Open AccessThe magnetization of antiferrmagnetic layer and the spin wave in the system of the exchange bias
Author(s) -
Jing Pan,
Zhou Lan,
Hu Jia
Publication year - 2009
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.58.6487
Subject(s) - magnetization , condensed matter physics , magnetocrystalline anisotropy , exchange bias , materials science , antiferromagnetism , spin wave , ferromagnetism , field (mathematics) , magnetic anisotropy , magnetic field , physics , quantum mechanics , mathematics , pure mathematics
Using a method of free energy minimizationthe spin wave of ferromagnetic FM/antiferromagnetic AFM bilayers was investigatedin which the net magnetization of AFM layer has been considered. In this modelthe thin FM layer is taken to be a single crystal with cubic and uniaxial magnetocrystalline anisotropiesbut AFM layer has only single uniaxial magnetocrystalline anisotropy and its thickness is finite. Numerical calculation shows that there are two modes of spin wavesnamely the acoustic mode and the optical mode. Moreover, only when there is net magnetization of AFM layer can the optical mode be observed. There are two branches of FMR curvesi.e. the branches of weak and strong external fieldwhich are distinguished by the critical fieldwhile the critical field depends on the exchange bias fieldthe magnetization and thickness of AFM layer. The effect of the exchange bias field on the optical mode is more obvious than that on the acoustic modewhile the effects groduced by net magnetization and thickness of AFM layer cant be distinguished. Howeverwhen the net magnetization of AFM layer is neglectedonly an acoustic mode is observed.