Abstract A modified magnetron sputtering setup was used to fabricate planar nanowire (NW) arrays of Co. The structural characterization of these polycrystalline Co NW arrays confirms the coexistence of both hcp and fcc phases, in which their relative fractions depend on the Co deposition time as well as the presence (or absence) of a bcc nanowire seed layer, as shown for tungsten case. A model to explain how the Co nanowires grow is proposed: hcp Co phase is firstly stabilized on the vicinal sapphire substrate (or W seed layer), but as the NW thickness increases, a structural relaxation leads to the fcc Co phase. While different contributions to the magnetic anisotropies are considered, we find that the magnetic properties are dominated by shape effects with an easy axis oriented along the average direction of the wire axis. Thicker NW arrays also have a significant contribution from the magnetocrystalline anisotropy. From the behavior of the temperature dependent magnetization, we find that for thicker nanowires the magnetization reversal is governed by a curling reversal mode, whereas thinner nanowires switch their magnetization via coherent rotation.

中文翻译：

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通过直流磁控溅射在邻近蓝宝石模板上生长的钴纳米线阵列

摘要 改进的磁控溅射装置用于制造 Co 的平面纳米线 (NW) 阵列。这些多晶 Co NW 阵列的结构表征证实了 hcp 和 fcc 相的共存，其中它们的相对分数取决于 Co 沉积时间，如以及 bcc 纳米线种子层的存在（或不存在），如钨情况所示。提出了一个解释 Co 纳米线如何生长的模型：hcp Co 相首先稳定在相邻的蓝宝石衬底（或 W 种子层）上，但随着 NW 厚度的增加，结构松弛导致 fcc Co 相。虽然考虑了对磁各向异性的不同贡献，但我们发现磁特性受形状效应支配，易轴沿线轴的平均方向取向。较厚的 NW 阵列也具有来自磁晶各向异性的显着贡献。根据温度相关磁化的行为，我们发现对于较厚的纳米线，磁化反转由卷曲反转模式控制，而较细的纳米线通过相干旋转来切换其磁化。