Nonmonotonic aftereffect measurements in perpendicular synthetic ferrimagnets
Nonmonotonic aftereffect measurements in perpendicular synthetic ferrimagnets
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DOI：
10.1103/physrevb.98.064410
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发表时间：
2018-08
影响因子：
3.7
通讯作者：
T. Fache;H. S. Tarazona;Jieyi Liu;G. L’vova;M. Applegate;J. Rojas-Sánchez;S. Petit-Watelot;C. Landauro;J. Quispe-Marcatoma;R. Morgunov;C. Barnes;S. Mangin
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文献类型：
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作者：
T. Fache;H. S. Tarazona;Jieyi Liu;G. L’vova;M. Applegate;J. Rojas-Sánchez;S. Petit-Watelot;C. Landauro;J. Quispe-Marcatoma;R. Morgunov;C. Barnes;S. Mangin
通过测量样品在几个不同外加磁场下的磁化强度随时间的变化，对表现出强烈垂直磁各向异性的合成亚铁磁体进行了后效测量，即(Co/Pt)/Ir/(Co/Pt)。观察到了意想不到的磁弛豫。事实上，对于某些特定的外加磁场，磁化强度作为时间的函数先是直线下降，然后又增加。这种非单调的后效可以通过考虑可能的磁态和这些态之间的跃迁来理解。这一认识已经用磁光克尔效应(MOKE)显微镜得到了证实和详细说明。事实上，测量结果显示了一种瞬变亚稳态磁组态的成核和传播。此外，我们能够得到一个简单的一维模型与实验观测的良好的定性一致。我们可以有力地支持这样的假设，即这种特殊的非单调行为可能是任何具有垂直磁各向异性的反铁磁耦合系统(合成亚铁磁体、合成反铁磁体)中应该观察到的非常普遍的特征。
Aftereffect measurements have been performed on synthetic ferrimagnets showing strong perpendicular magnetic anisotropy, namely (Co/Pt)/Ir/(Co/Pt), by measuring the magnetization of the sample as a function of time for several different applied magnetic fields. Unexpected magnetic relaxation has been observed. Indeed, for some particular applied magnetic fields, the magnetization as a function of time first plummets and then increases. This nonmonotonic aftereffect can be understood by considering the possible magnetic states and the transitions between those states. This understanding has been confirmed and detailed using magneto-optical Kerr effect (MOKE) microscopy. Indeed, the measurements show nucleation and propagation of a transient metastable magnetic configuration. Furthermore, we were able to obtain a good qualitative agreement between a simple one-dimensional model and the experimental observation. We could strongly support the hypothesis that this peculiar nonmonotonic behavior could be a very general feature that should be observed in any antiferromagnetically coupled system (synthetic ferrimagnets, synthetic antiferromagnets) with perpendicular magnetic anisotropy.