Cheng Hongfei, Yang Nailiang, Liu Xiaozhi, Guo Yilv, Liu Bin, Yang Jianhui, Chen Ye, Chen Bo, Fan Zhanxi, Lu Qipeng, Yuan Shijun, Wang Jinlan, Gu Lin, Zhang Hua
Center for Programmable Materials, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, No. 1 Beiertiao, Zhongguancun, Beijing, 100190, China.
Adv Mater. 2021 Jan;33(1):e2007140. doi: 10.1002/adma.202007140. Epub 2020 Nov 26.
Phase engineering of nanomaterials is an effective strategy to tune the physicochemical properties of nanomaterials for various promising applications. Herein, by using the 4H-Au nanoribbons as templates, four novel magnetic nanostructures, namely 4H-Au @ 14H-Co nanobranches, 4H-Au @ 14H-Co nanoribbons, 4H-Au @ 2H-Co nanoribbons, and 4H-Au @ 2H-Ni nanoribbons, are synthesized based on the quasi-epitaxial growth. Different from the conventional epitaxial growth of metal nanomaterials, the obtained Co and Ni nanostructures possess different crystal phases from the Au template. Due to the large lattice mismatch between Au and the grown metals (i.e., Co and Ni), ordered misfit dislocations are generated at the Co/Au and Ni/Au interfaces. Notably, a new super-structure of Co is formed, denoted as 14H. Both 4H-Au @ 14H-Co nanobranches and nanoribbons are ferromagnetic at room temperature, showing similar Curie temperature. However, their magnetic behaviors exhibit distinct temperature dependence, resulting from the competition between spin and volume fluctuations as well as the unique geometry. This work paves the way to the templated synthesis of nanomaterials with unconventional crystal phases for the exploration of phase-dependent properties.
纳米材料的相工程是一种有效的策略，可调节纳米材料的物理化学性质以用于各种有前景的应用。在此，以4H金纳米带为模板，基于准外延生长合成了四种新型磁性纳米结构，即4H-Au@14H-Co纳米分支、4H-Au@14H-Co纳米带、4H-Au@2H-Co纳米带和4H-Au@2H-Ni纳米带。与金属纳米材料的传统外延生长不同，所获得的钴和镍纳米结构与金模板具有不同的晶相。由于金与生长的金属（即钴和镍）之间存在较大的晶格失配，在Co/Au和Ni/Au界面处产生了有序的失配位错。值得注意的是，形成了一种新的钴超结构，记为14H。4H-Au@14H-Co纳米分支和纳米带在室温下均为铁磁性，显示出相似的居里温度。然而，由于自旋和体积涨落之间的竞争以及独特的几何形状，它们的磁行为表现出明显的温度依赖性。这项工作为模板合成具有非常规晶相的纳米材料以探索相依赖性质铺平了道路。
