Polymer-Assisted Synthesis, Structure and Magnetic Properties of Bimetallic FeCo- and FeNi/N-Doped Carbon Nanocomposites

Abstract

Bimetallic FeCo and FeNi nanoparticles attract much attention due to their promising magnetic properties and a wide range of practical applications as recording and storage media, catalytic systems in fuel cells, supercapacitors, lithium batteries, etc. In this paper, we propose an original approach to the preparation of FeCo- and FeNi/N-doped carbon nanocomposites by means of a coupled process of frontal polymerization and thermolysis of molecular co-crystallized acrylamide complexes. The phase composition, structure, and microstructure of the resulting nanocomposites are studied using XRD, IR spectroscopy, elemental and thermal analysis, and electron microscopy data. The main magnetic characteristics of the synthesized nanocomposites, including the field dependences and the ZFC-FC curves peculiarities, are studied. It is shown that the obtained FeCo/N-C nanocomposites exhibit exchange bias behavior at low temperatures. In turn, FeNi/N-C nanocomposites are ferromagnetically ordered.

Experimental Thermal Conductivity Studies of Agar-Based Aqueous Suspensions with Lignin Magnetic Nanocomposites

“…Polymers are also attractive coating materials for inorganic nanoparticles, which generate nanocomposites with enhanced thermal conductivity capable of performing as thermal interface materials for thermal management applications [26]. Bimetallic iron nanocomposites have also shown enhanced magnetic characteristics at different temperatures [27]. However, to our knowledge, there is a lack of thermal conductivity studies of bio-based polymer nanocomposites, including lignin@Fe 3 O 4 .…”

Frontal Polymerization for the Rapid Obtainment of Polymer Composites

“…26 Recently, Kugabaeva and co-workers succeeded in obtaining magnetically active bimetallic nanoparticles (namely FeCo and FeNi) of a given composition and stabilized by an N-doped carbonized polymer matrix, which were simultaneously formed during the FP of suitable molecular precursors (namely cocrystallized acrylamide complexes of Fe(III)/Co(II) and Fe(III)/Ni(II) metal nitrates) and their successive controlled thermolysis. 27 The overall process is schematized in Figure 6. The so-obtained magnetic nanoparticles were found to be resistant to oxidation and aggregation; further, the frontal polymerization technique allowed for effective control of the size of nanoparticles and, finally, of their magnetic features.…”

“…Recently, Kugabaeva and co-workers succeeded in obtaining magnetically active bimetallic nanoparticles (namely FeCo and FeNi) of a given composition and stabilized by an N-doped carbonized polymer matrix, which were simultaneously formed during the FP of suitable molecular precursors (namely cocrystallized acrylamide complexes of Fe­(III)/Co­(II) and Fe­(III)/Ni­(II) metal nitrates) and their successive controlled thermolysis . The overall process is schematized in Figure .…”

“…AAm: acrylamide; FeCoAAm: FeCo acrylamide complex; FeNiAAm: FeNi acrylamide complex; FeCoPAAm: FeCo polyacrylamide complex; FeNiPAAm: FeNi polyacrylamide complex; FeCo/C–N: FeCo/N-doped carbon nanocomposite; FeNi/C–N: FeNi/N-doped carbon nanocomposite. Reprinted from ref ( 27 ) under CC-BY license.…”