Nanospheres of a New Intermetallic FeSn5 Phase: Synthesis, Magnetic Properties and Anode Performance in Li-ion Batteries

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• 作者：Xiao-Liang Wang ; Mikhail Feygenson ; Haiyan Chen ; Chia-Hui Lin ; Wei Ku ; Jianming Bai ; Meigan C. Aronson ; Trevor A. Tyson ; Wei-Qiang Han
• 刊名：Journal of the American Chemical Society
• 出版年：2011
• 出版时间：July 27, 2011
• 年：2011
• 卷：133
• 期：29
• 页码：11213-11219
• 全文大小：904K
• 年卷期：v.133,no.29(July 27, 2011)
• ISSN：1520-5126

文摘

We synthesized monodisperse nanospheres of an intermetallic FeSn₅ phase via a nanocrystal-conversion protocol using preformed Sn nanospheres as templates. This tetragonal phase in P4/mcc space group, along with the defect structure Fe_0.74Sn₅ of our nanospheres, has been resolved by synchrotron X-ray diffraction and Rietveld refinement. Importantly, FeSn₅, which is not yet established in the Fe鈥揝n phase diagram, exhibits a quasi-one dimensional crystal structure along the c-axis, thus leading to interesting anisotropic thermal expansion and magnetic properties. Magnetization measurements indicate that nanospheres are superparamagnetic above the blocking temperature T_B = 300 K, which is associated with the higher magnetocrystalline anisotropy constant K = 3.33 kJ m^鈥?. The combination of the magnetization measurements and first-principles density functional theory calculations reveals the canted antiferromagnetic nature with significant spin fluctuation in lattice a鈥?i>b plane. The low Fe concentration also leads Fe_0.74Sn₅ to enhanced capacity as an anode in Li ion batteries.