Phase transitions in Co thin film induced by low energy and high energy ion beam irradiation
Phase transitions in Co thin film induced by low energy and high energy ion beam irradiation
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DOI：
10.1063/1.3294609
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发表时间：
2010-02
影响因子：
3.2
通讯作者：
R. Gupta;A. Khandelwal;D. Avasthi;K. Nair;A. Gupta
中科院分区：
文献类型：
--
作者：
R. Gupta;A. Khandelwal;D. Avasthi;K. Nair;A. Gupta
离子辐照通过高的局域能量沉积和缺陷积累，对微晶结构和相应的磁各向异性起着重要的调节作用。在本工作中，我们研究了核能量损失和电子能量损失对多晶Co薄膜的相变和磁各向异性的影响。与HCP-Co薄膜不同，沉积时的薄膜表现出具有两重单轴磁各向异性的多晶行为。320keV的Au离子引起了从六方相到面心立方的相变。在120 MeV Au离子辐照的薄膜中也观察到了类似的相变。根据电子和核能量损失讨论了相变速率，并根据单轴和四重磁各向异性讨论了磁各向异性行为的相应变化。
Ion irradiation plays an important role to tailor the microcrystalline structure and the corresponding magnetic anisotropy by high local energy deposition and defect accumulation. In the present work, we have investigated the effects of nuclear energy loss and electronic energy loss on the phase transformation and magnetic anisotropy of thin polycrystalline Co films. As-deposited film shows polycrystalline behavior with twofold uniaxial magnetic anisotropy, characteristic to hcp-Co film. 320 keV Au ions induce phase transformation from hcp to fcc. Similar phase transformation have been observed in the case of film irradiated by 120 MeV Au ions. Rate of phase transformation is discussed in terms of electronic and nuclear energy losses and the corresponding changes in the magnetic anisotropic behavior are discussed in the light of uniaxial and fourfold magnetic anisotropy.