Nady Norhan, Salem Noha, Mohamed Marwa A A, Kandil Sherif H
Polymeric Materials Research Department, City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Alexandria 21934, Egypt.
Department of Materials Science, Institute of Graduate Studies and Research, Alexandria University, Alexandria 21526, Egypt.
Nanomaterials (Basel). 2021 Nov 12;11(11):3034. doi: 10.3390/nano11113034.
Iron-nickel alloy is an example of bimetallic nanostructures magnetic alloy, which receives intensive and significant attention in recent years due to its desirable superior ferromagnetic and mechanical characteristics. In this work, a unique starfish-like shape of an iron-nickel alloy with unique magnetic properties was presented using a simple, effective, high purity, and low-cost chemical reduction. There is no report on the synthesis of such novel shape without complex precursors and/or surfactants that increase production costs and introduce impurities, so far. The synthesis of five magnetic iron-nickel alloys with varying iron to nickel molar ratios (10-50% Fe) was undertaken by simultaneously reducing Fe(II) and Ni(II) solution using hydrazine hydrate as a reducing agent in strong alkaline media for 15 min at 95-98 °C. The effect of reaction volume and total metal concentration on the properties of the synthesized alloys was studied. Alloy morphology, chemical composition, crystal structure, thermal stability, and magnetic properties of synthesized iron-nickel alloys were characterized by means of SEM, TEM, EDX, XRD, DSC and VSM. ImageJ software was used to calculate the size of the synthesized alloys. A deviation from Vegard's law was recorded for iron molar ration higher than 30%., in which superstructure phase of FeNi was formed and the presence of defects in it, as well as the dimensional effects of nanocrystals. The saturation magnetization (Ms), coercivity (Hc), retentivity (Mr), and squareness are strongly affected by the molar ratio of iron and nickel and reaction volume as well as the total metal concentration.
铁镍合金是双金属纳米结构磁性合金的一个例子，近年来因其优异的铁磁和机械特性而受到广泛关注。在这项工作中，通过简单、有效、高纯度且低成本的化学还原法制备出了具有独特磁性的海星状铁镍合金。到目前为止，尚无关于在不使用增加生产成本并引入杂质的复杂前驱体和/或表面活性剂的情况下合成这种新颖形状合金的报道。在强碱性介质中，于95 - 98°C下使用水合肼作为还原剂同时还原Fe(II)和Ni(II)溶液15分钟，制备了五种铁与镍摩尔比不同（铁含量为10 - 50%）的磁性铁镍合金。研究了反应体积和总金属浓度对合成合金性能的影响。通过扫描电子显微镜（SEM）、透射电子显微镜（TEM）、能谱仪（EDX）、X射线衍射仪（XRD）、差示扫描量热仪（DSC）和振动样品磁强计（VSM）对合成的铁镍合金的合金形态、化学成分、晶体结构、热稳定性和磁性进行了表征。使用ImageJ软件计算合成合金的尺寸。当铁摩尔比高于30%时，记录到与维加德定律的偏差，其中形成了FeNi的超结构相，且其中存在缺陷以及纳米晶体的尺寸效应。饱和磁化强度（Ms）、矫顽力（Hc）、剩磁（Mr）和矩形比受到铁和镍的摩尔比、反应体积以及总金属浓度的强烈影响。
