Current Applied Physics ( IF 2.4 ) Pub Date : 2021-03-08 , DOI: 10.1016/j.cap.2021.02.013 Ruslan D. Ivantsov , Chun-Rong Lin , Oxana S. Ivanova , Roman R. Altunin , Yuriy V. Knyazev , Maxim S. Molokeev , Sergey M. Zharkov , Ying-Zhen Chen , En-Szu Lin , Bing-Yi Chen , Nikolai P. Shestakov , Irina S. Edelman
Greigite (Fe3S4) nanoparticles (NPs) were fabricated by the thermal decomposition method using two different surfactants: oleylamine (OLA) and 1-hexadecylamine (HDA). In both cases, the synthesized NPs were characterized as the Fe3S4 nanocrystals with minor inclusions of Fe9S11 phase. FT-IR spectroscopy and thermo-gravimetric analysis allow concluding about OLA or HDA shells covering magnetic core of NPs. Mössbauer spectra has revealed deviations of iron ions distribution among crystal positions from that presented in literature for pure greigite. In accordance with these deviations, the pronounce changes are observed in the magnetic circular dichroism (MCD) spectra which manifest themselves as the spectrum shift to higher energies of electromagnetic waves and redistribution of the MCD maximum intensities. These effects are associated with a change in the density of electronic states in the samples due to the redistribution of iron ions between octahedral and tetrahedral positions in nanocrystals under the influence of surfactants.
中文翻译:
用两种不同的表面活性剂通过热分解方法合成的Fe 3 S 4纳米粒子的Mössbauer和MCD光谱
通过热分解方法,使用两种不同的表面活性剂:油胺(OLA)和1-十六烷基胺(HDA)制备了方铅矿(Fe 3 S 4)纳米颗粒(NPs)。在这两种情况下,合成的NPs均被表征为Fe 3 S 4纳米晶体,其中含有少量的Fe 9 S 11夹杂物。阶段。FT-IR光谱和热重分析可以得出关于覆盖NP磁芯的OLA或HDA壳的结论。Mössbauer光谱揭示了晶体位置中铁离子的分布与纯钙镁石中文献报道的存在偏差。根据这些偏差,在圆圆二色性(MCD)光谱中观察到了明显的变化,这表现为随着光谱向更高能量的电磁波偏移以及MCD最大强度的重新分布。这些影响与样品中电子态密度的变化有关,这归因于在表面活性剂的影响下铁离子在纳米晶体中八面体和四面体位置之间的重新分布。