Anomalous magnetic behavior in nanocomposite materials of reduced graphene oxide-Ni/NiFe2O4

Abstract

Magnetic Reduced Graphene Oxide-Nickel/NiFe2O4 (RGO-Ni/NF) nanocomposite has been synthesized by one pot solvothermal method. Respective phase formations and their purities in the composite are confirmed by High Resolution Transmission Electron Microscope and X Ray Diffraction, respectively. For the RGO-Ni/NF composite material finite-size effects lead to the anomalous magnetic behavior, which is corroborated in temperature and field dependent magnetization curves. Here, we are reporting the behavior of higher magnetization values for Zero Field Cooled condition to that of Field Cooled for the RGO-Ni/NF nanocomposite. Also, the observed negative and positive moments in Hysteresis loops at relatively smaller applied fields (100 Oe and 200 Oe) are explained on the basis of surface spin disorder.

CoFe2O4 and NiFe2O4@graphene adsorbents for heavy metal ions – kinetic and thermodynamic analysis

“…S1b †). 21 Aer the reduction of GO to graphene by solvothermal process, the reduced GO sheets were exfoliated and decorated by the CoFe 2 O 4 and NiFe 2 O 4 nanoparticles. This process might have led to the disappearance of the diffraction peaks of graphene (002) in accordance with the earlier reports.…”

Characterization of an active ingredient made of nanoscale iron(oxyhydr)oxide for the treatment of hyperphosphatemia

“…If the external magnetic eld is sufficiently small, these interactions can lead to unpaired spin systems, which lead to this anomalous behavior of the temperature-dependent magnetization curves. 77 In addition, the measured blocking temperature is extremely low compared to other iron(oxyhydr)oxide nanoparticles. 47,52,62,76 However, it should be noted that the blocking temperature depends on the crystal size as well as on the distance between the crystallites.…”

“…46,47,52,62,75,76 It is, however, unusual that the ZFC magnetization is partly higher than the FC magnetization between 4.7 K and 10 K. The same effect was observed by Kollu et al for a nano compound made of reduced graphene oxide-nickel and nickel ferrite. 77 This atypical behavior was evident when recording the ZFC and FC magnetization at low magnetic elds (100 and 200 Oe). The phenomenon disappeared at higher magnetic elds (500 and 2000 Oe) and the curves behaved as expected.…”

“…If the external magnetic field is sufficiently small, these interactions can lead to unpaired spin systems, which lead to this anomalous behavior of the temperature-dependent magnetization curves. 77 …”

Facile Mechanochemical Synthesis of Nickel/Graphene Oxide Nanocomposites with Unique and Tunable Morphology: Applications in Heterogeneous Catalysis and Supercapacitors

“…For instance, Chen and co-workers [21] synthesized nickel/graphene hybrids under microwave irradiation by using NaHB 4 as a reducing agent and NaOH as an alkaline medium. Kollu et al [22] adopted one-pot solvothermal method for preparation of RGO-Ni/NF nanocomposite in which ethylene glycol was used to avoid unnecessary aggregation or growth of Ni NPs. Similarly, Ji et al [23] prepared RGO/Ni nanocomposites by using NaHB 4 and NaOH as a reducing agent and alkaline medium.…”