Chemical Synthesis of High-Stable Amorphous FeCo Nanoalloys with Good Magnetic Properties

Abstract

It is difficult to fabricate high-purity amorphous FeCo alloys by traditional physical methods due to their weak glass forming ability. In this work, the fully amorphous FeCo nanoalloys with high purity and good stability have been prepared by a direct chemical reduction of Fe2+ and Co2+ ions with NaBH4 as the reducing agent and polyvinylpyrrolidone (PVP) as the surfactant. The morphologies, surface compositions and particle sizes with their distribution of these amorphous samples can be effectively tuned by the suitable PVP additions. High crystallization temperature up to 468 °C, high saturation magnetization of 196.2 A·m2·kg−1 and low coercivity of 83.3 Oe are obtained in amorphous FeCo nanoalloys due to their uniform distribution, weak surface oxidation and low surface B concentration. Good frequency-dependent magnetic properties can be also achieved in the fully compacted amorphous sample with a high density of 7.20 g/cm3. The simple chemical method, high stability and good magnetic properties for these amorphous FeCo nanoalloys promise their significant potential applications in high-power magnetic devices.

Amorphous FexCo1–x Wire-like Nanostructures Manufactured through Surfactant-Free Magnetic-Field-Induced Synthesis

“…7,41 In turn, the ED patterns registered for all Fe−Co chains look very similar, and they consist of two highly diffuse rings which are characteristic for nanocrystalline or amorphous materials. 45,52,58,59 Surprisingly, these diffraction rings can be assigned to the (110) and (211) crystal planes typically present in a body-centered cubic (bcc) structure of the Fe−Co alloy, whereas the ring corresponding to the (200) plane is not recorded. 46,60−62 Undoubtedly, this is related to the amorphous nature of the Fe−Co nanomaterials.…”

“…In contrast, as already demonstrated, the same synthesis procedures without application of the external magnetic field led to the formation of the Fe and Fe−Co nanoparticles. 51,52,54 It is also important to mention that even if the same external magnetic field was applied in the synthesis with a precursor containing cobalt ions, only cobalt nanoparticles (Co NPs) with an average diameter of about 78 nm were obtained in this process. Nevertheless, to the best of our knowledge no research paper, in which the MFI synthesis procedures of cobalt wire-like nanostructures without additional usage of surfactants, complexing or chelating agents, initiators, and/or organic solvents, has been published so far.…”

“…Fabrication of Iron−Cobalt Wire-like Nanostructures. Iron− cobalt wire-like nanostructures were manufactured through the magnetic-field-induced chemical co-reduction reaction based on the previously established syntheses of amorphous Fe−Co nanoparticles 51,52 and iron nanowires. 53−55 In general, the process was performed in a glass reactor filled with 300 mL of aqueous solution containing various contents of iron(II) chloride hydrate and cobalt(II) chloride hexahydrate.…”

Non-Supported Nickel-Based Coral Sponge-Like Porous Magnetic Alloys for Catalytic Production of Syngas and Carbon Bio-Nanofilaments via a Biogas Decomposition Approach

“…Bimetallic alloys have been synthesized using various physical and chemical techniques, including sol–gel [21], hydrothermal [22], pyrolysis [23], sonochemical [24], radiolysis [25], microwave combustion [26], microemulsion [27], impregnation [28], and precipitation [29]. However, investigation of the synthesis of bimetallic magnetic alloys is still attractive to researchers [30,31,32,33].…”

A systematic computational study of electronic, mechanical, and optical properties of Fe1−xCox alloy

“…Many experimental research have been performed on structural and magnetic properties of FeCo alloys [10,12,13]. However, based on composition, only a very few computational studies have focused on electronic, magnetic, and mechanical properties.…”