近年来,由稀土元素和3d过渡金属构成的亚铁磁材料受到广泛的关注.亚铁磁材料既具有同铁磁材料一样的净余磁矩,又有反铁磁材料的超快动力学特征,这些性质使其成为自旋电子学领域的研究热点之一.在本工作中,采用磁控溅射的方法制备了亚铁磁GdCo/Cu/Permalloy(Py)异质结,通过自旋-轨道铁磁共振(spin-orbit ferromagnetic resonance,ST-FMR)的方法研究了样品的磁化动力学和自旋传输特性,并分析了所制备样品的铁磁共振阻尼与 自旋轨道矩效率.结果表明,所制备GdCo/Cu/Py异质结的自旋轨道矩(spin orbital torque,SOT)效率为-0.08,略低于重金属Pt的自旋霍尔角.同时铁磁共振阻尼分析也显示出GdCo/Cu/Py异质结中没有显著的自旋泵浦效应,导致这种现象的原因可能是界面处自旋传输的非互易性.研究证明亚铁磁GdCo薄膜不同于铁磁性材料的动态磁化特性,显示出其物理研究价值和实际应用潜力.
Abstract
Recently,ferrimagnetic materials composed of rare earth elements and 3d transition metals have received extensive attention.Ferrimagnetic materials have the adjustable net magnetization,as well as the antiferromagnetic-like ultrafast magnetic dynamic behavior,which make it become one of the popular research fields in spintronic.In this work,we prepared the ferrimagnetic GdCo/Cu/Permaloy(Py)heterostructure by magnetron sputtering system.The magnetic dynamic and spin transfer characters of the sample were studied by using the spin-orbit ferromagnetic resonance.The spin orbital torque efficiency of the prepared GdCo/Cu/Py heterstructure is-0.08,which is slightly lower than the spin Hall angle of heavy metal Pt.The damping analysis shows negligible spin pumping effect in the GdCo/Cu/Py heterstructure.We attribute this phenomenon to the non-reciprocity of spin transfer at the interface.Our work shows the unique magnetic dynamic properties of ferrimagnetic GdCo film,showing its practical application potential.
维普
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