在二维复式正方Heisenber铁磁系统的基础上建立了磁振子-声子相互作用模型,利用松原格林函数理论研究了系统T→OK下的磁振子衰减,计算了布里渊区的主要对称点线上的磁振子衰减的变化曲线,比较了磁性离子的与非磁性离子的光频支声子对磁振子衰减的影响以及各项参数的变化对磁振子衰减的影响,发现光频支声子-磁振子耦合对磁振子衰减起主要作用,尤其是纵向光频支声子对磁振子衰减起更大的作用,并且非磁性离子的光频支声子对磁振子衰减的作用比磁性离子的光频支声子对磁振子衰减的作用更显著.根据关系式-Im∑*(1)(k)=h/(2τ)可以对磁振子寿命和磁振子线宽进行判断.
A magnon-phonon interaction model is set up in a two-dimensional ferromagnetic double square-lattice system. By using Matsubara Green function theory we have studied the magnon damping of the system at temperature of T→OK, cal-culated the magnon damping change curves on the main symmetric line in the Brillouin zone, compared the influences of magnetic ion optical-mode phonon and non-magnetic ion optical-mode phonon on the magnon damping of the system, and dis-cussed the influences of the parameter variations on the magnon dainping. The results show that the coupling of the optical-mode phonon and magnon plays the main role for the magnon damping, especially, the longitudinal optical-mode phonon con-tributes the most for the magnon damping. It is also found that the effect of the nonmagnetic ion on magnon damping is more significant than that of the magnetic ion. According to expression-Im∑*(1)(k)=h/(2τ), the magnon life-time is dis-cussed,
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