Elastic Constants and Magnetic Anisotropy of Co/Pt Superlattice: Resonance-Ultrasound-Spectroscopy Method
Elastic Constants and Magnetic Anisotropy of Co/Pt Superlattice: Resonance-Ultrasound-Spectroscopy Method
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Co/Pt 超晶格的弹性常数和磁各向异性：共振超声能谱法
DOI：
10.1143/jjap.44.4427
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发表时间：
2005
影响因子：
1.5
通讯作者：
M. Nishiyama
中科院分区：
文献类型：
--
作者：
N. Nakamura;H. Ogi;T. Ono;M. Hirao;M. Nishiyama
Co/Pt超晶格表现出垂直磁各向异性，当Co层厚度小于约20 μ m时，使Co层的磁化方向垂直于薄膜表面。垂直磁各向异性的一个可能原因是Co和Pt层之间的界面处的大弹性应变。弹性应变还通过晶格非谐性改变Co/Pt超晶格的宏观弹性常数。在这项研究中，我们确定了各向异性的弹性常数的Co/Pt超晶格薄膜使用共振超声光谱耦合激光/多普勒干涉法，并研究了弹性和磁性之间的关系。我们清楚地观察到它们之间的相关性，这是解释在晶格非谐性。
The Co/Pt superlattice shows perpendicular magnetic anisotropy, which makes the magnetization direction of the Co layer perpendicular to the film surface when the Co layer is less than about 20 Å thick. One possible cause of perpendicular magnetic anisotropy is large elastic strain at the interfaces between the Co and Pt layers. The elastic strain also changes the macroscopic elastic constants of the Co/Pt superlattice through lattice anharmonicity. In this study, we determined the anisotropic elastic constants of Co/Pt superlattice thin films using resonance ultrasound spectroscopy coupled with the laser/Doppler-interferometry method and studied the relationship between elastic and magnetic properties. We clearly observe a correlation between them, which is interpreted in terms of lattice anharmonicity.