Krajewski Marcin, Liou Sz-Chian, Jurkiewicz Karolina, Brzózka Katarzyna, Chiou Wen-An, Kubacki Jerzy, Burian Andrzej
Institute of Fundamental Technological Research, Polish Academy of Sciences, Pawińskiego 5B, 02-106 Warsaw, Poland.
Advanced Imaging and Microscopy Laboratory, Maryland Nano Center, Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD, 20742-2831, USA.
Phys Chem Chem Phys. 2021 Dec 22;24(1):326-335. doi: 10.1039/d1cp04411g.
Preparation and detailed structural characterization of iron-nickel wire-like nanochains with FeNi, FeNi, and FeNi compositions are reported. The investigated nanomaterials were produced by the novel template-free magnetic-field-induced reduction reaction with NaBH as the reducing agent. It is demonstrated that this method leads to the formation of Fe-Ni nanochains composed of spherical nanoparticles with an average diameter of 50-70 nm and with a very high degree of atomic disorder manifested as the lack of clearly developed bcc and fcc phases, which are usually observed for nano- and polycrystalline Fe-Ni species. The recorded wide-angle X-ray scattering data for the obtained Fe-Ni nanochains exhibit a strong resemblance to those obtained for bulk metallic glasses. The atomic scale structure of the investigated nanochains has been studied using pair distribution function analysis of the recorded total scattering data. The best fits to the experimental pair distribution functions have been achieved assuming two-phase models of hcp and bcc networks with the size of coherently scattering regions of about 2.5 nm in diameter, for each Fe-Ni composition. The transmission electron microscopy images indicate that the glass-like bimetallic alloy cores are covered by amorphous oxide/hydroxide shells with their thickness ranging from 2 to 5 nm. Moreover, electron energy loss spectroscopy, X-ray photoelectron spectroscopy, and Mössbauer spectroscopy results confirm the core-shell structure of the Fe-Ni nanochains and the complex character of the shell layer which consists of several iron- and nickel-containing phases.
报道了具有FeNi、FeNi和FeNi组成的铁镍线状纳米链的制备及其详细的结构表征。所研究的纳米材料是通过以NaBH为还原剂的新型无模板磁场诱导还原反应制备的。结果表明，该方法导致形成由平均直径为50 - 70 nm的球形纳米颗粒组成的Fe-Ni纳米链，并且具有非常高的原子无序度，表现为缺乏通常在纳米和多晶Fe-Ni物种中观察到的明显发育的体心立方（bcc）和面心立方（fcc）相。所获得的Fe-Ni纳米链的广角X射线散射数据与块状金属玻璃的散射数据非常相似。利用记录的总散射数据的对分布函数分析研究了所研究纳米链的原子尺度结构。对于每种Fe-Ni组成，假设六方密堆积（hcp）和体心立方（bcc）网络的两相模型，相干散射区域直径约为2.5 nm，从而实现了与实验对分布函数的最佳拟合。透射电子显微镜图像表明，玻璃状双金属合金核被厚度为2至5 nm的非晶氧化物/氢氧化物壳覆盖。此外，电子能量损失谱、X射线光电子能谱和穆斯堡尔谱结果证实了Fe-Ni纳米链的核壳结构以及壳层的复杂性质，壳层由几个含铁和镍的相组成。
