Abstract

Triple FeCoNi nanoparticles, distributed and stabilized in the carbon matrix of FeCoNi/C metal-carbon nanocomposites, are synthesized. The nanocomposites are synthesized by the method of controlled IR pyrolysis of precursors of the polymer-metal nitrate type obtained by the joint dissolution of the components followed by removal of the solvent. The effect of the synthesis temperature on the structure, composition, and electromagnetic properties of nanocomposites is investigated. It is shown by XRD that the formation of ternary FeCoNi nanoparticles occurs due to the dissolution of Fe in the nanoparticles of a NiCo solid solution. With an increase in the synthesis temperature, the size of metal nanoparticles increases, which is determined by the processes of their agglomeration and coalescence during the matrix rearrangement. Also, depending on the synthesis temperature, nanoparticles of a ternary alloy with different compositions can be formed, and the ratio of metals specified in the precursor is achieved at 700°C. It is shown by Raman spectroscopy that with an increase in the synthesis temperature, the degree of crystallinity of the carbon matrix of nanocomposites increases, and graphene structures consisting of several layers can be formed. The frequency dependences of the relative complex dielectric and magnetic permeability of nanocomposites in the 3–13 GHz range are investigated. It is shown that an increase in the synthesis temperature leads to a significant increase in both dielectric and magnetic losses (by a factor of ~2). The former are related to the formation of a complex nanostructure of the carbon matrix of the nanocomposite, while the latter are determined by an increase in the size of nanoparticles and a shift in the natural ferromagnetic resonance (NFMR) frequency to the low-frequency region. Reflection loss (RL) calculations are carried out according to the standard technique based on experimental data on the frequency dependences of the permeability and permittivity. It is shown that the frequency range and the magnitude of the absorption of electromagnetic waves (from 50 to 94%) can be regulated by changing the temperature of the synthesis of nanocomposites.

中文翻译：

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基于聚乙烯醇的FeCoNi/C纳米复合材料的合成及电磁性能

摘要

合成了分布并稳定在 FeCoNi/C 金属-碳纳米复合材料的碳基质中的三重 FeCoNi 纳米颗粒。纳米复合材料是通过聚合物-金属硝酸盐类型的前体的受控红外热解方法合成的，该前体通过组分的联合溶解然后去除溶剂而获得。研究了合成温度对纳米复合材料的结构、组成和电磁性能的影响。XRD表明，三元FeCoNi纳米颗粒的形成是由于Fe溶解在NiCo固溶体的纳米颗粒中。随着合成温度的升高，金属纳米粒子的尺寸增大，这是由它们在基体重排过程中的团聚和聚结过程决定的。还，根据合成温度的不同，可以形成具有不同成分的三元合金纳米颗粒，并且在700℃下达到前驱体中规定的金属比例。拉曼光谱表明，随着合成温度的升高，纳米复合材料的碳基体的结晶度增加，可以形成由多层组成的石墨烯结构。研究了在 3-13 GHz 范围内纳米复合材料的相对复杂介电和磁导率的频率依赖性。结果表明，合成温度的升高会导致介电损耗和磁损耗显着增加（约 2 倍）。前者与纳米复合材料的碳基体形成复杂的纳米结构有关，而后者是由纳米颗粒尺寸的增加和自然铁磁共振（NFMR）频率向低频区域的转移决定的。反射损耗 (RL) 计算是根据基于关于磁导率和介电常数的频率依赖性的实验数据的标准技术进行的。结果表明，可以通过改变纳米复合材料合成的温度来调节电磁波吸收的频率范围和幅度（从 50% 到 94%）。反射损耗 (RL) 计算是根据基于关于磁导率和介电常数的频率依赖性的实验数据的标准技术进行的。结果表明，可以通过改变纳米复合材料合成的温度来调节电磁波吸收的频率范围和幅度（从 50% 到 94%）。反射损耗 (RL) 计算是根据基于关于磁导率和介电常数的频率依赖性的实验数据的标准技术进行的。结果表明，可以通过改变纳米复合材料合成的温度来调节电磁波吸收的频率范围和幅度（从 50% 到 94%）。