The magnetic inertial dynamics have previously been investigated for one sublattice ferromagnets. Here, we develop the magnetization dynamics in two-sublattice ferromagnets including the intra- and inter-sublattice inertial dynamics. First, we derive the magnetic susceptibility of such a ferromagnet. Next, by finding the poles of the susceptibility, we calculate the precession and nutation resonance frequencies. Our results suggest that while the resonance frequencies show decreasing behavior with the increasing intra-sublattice relaxation time, the effect of inter-sublattice inertial dynamics has an opposite effect.

中文翻译：

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二亚晶格铁磁体中的磁惯性动力学理论

先前已经研究了一种亚晶格铁磁体的磁惯性动力学。在这里，我们开发了两个亚晶格铁磁体的磁化动力学，包括亚晶格内和亚晶格间惯性动力学。首先，我们推导出这种铁磁体的磁化率。接下来，通过找到磁化率的极点，我们计算进动和章动共振频率。我们的结果表明，虽然共振频率显示出随着亚晶格内弛豫时间的增加而降低的行为，但亚晶格间惯性动力学的影响具有相反的效果。