Enhanced magnetic anisotropy and heating efficiency in multi-functional manganese ferrite/graphene oxide nanostructures

Abstract

A promising nanocomposite material composed of MnFe2O4 (MFO) nanoparticles of ~17 nm diameter deposited onto graphene oxide (GO) nanosheets was successfully synthesized using a modified co-precipitation method. X-ray diffraction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED) confirmed the quality of the synthesized samples. Fourier Transform Infrared (FTIR) measurements and analysis evidenced that the MFO nanoparticles were attached to the GO surface. Magnetic measurements and analysis using the modified Langevin model evidenced the superparamagnetic characteristic of both the bare MFO nanoparticles and the MFO-GO nanocomposite at room temperature, and an appreciable increase of the effective anisotropy for the MFO-GO sample. Magnetic hyperthermia experiments performed by both calorimetric and AC magnetometry methods indicated that relative to the bare MFO nanoparticles, the heating efficiency of the MFO-GO nanocomposite was similar at low ac fields (0-300 Oe) but became progressively larger with increasing ac fields (> 300 Oe). This has been related to the higher effective anisotropy of the MFO-GO nanocomposite. In comparison with the bare MFO nanoparticles, a smaller reduction in the heating efficiency was observed in the MFO-GO composites when MFO-GO were embedded in agar or when their concentration was increased, indicating that the GO helped minimize the physical rotation and aggregation of the MFO nanoparticles. These findings can be of practical importance in exploiting this type of nanocomposite for advanced hyperthermia. Magnetoimpedance-based biodetection studies also indicated that the MFO-GO nanocomposite could be used as a promising magnetic biomarker in biosensing applications.

High Frequency Hysteresis Losses on γ-Fe2O3 and Fe3O4: Susceptibility as a Magnetic Stamp for Chain Formation

“…This new technology allows for deeper investigation in the understanding of the magnetic properties that optimizes the nanoparticle heating efficiencies and, due to the short measurement times (few seconds), allows a magnetic characterization at almost constant temperature, giving more reliable results than calorimetry characterizations, in which magnetic properties change with a temperature increase. For example, with this technique, it is possible to study the effect of size, effective anisotropy, colloidal viscosity, or dipolar interactions on the hysteresis cycles [12,30,31,32,33,34,35]. Additionally, by means of numerical simulations, it is possible to investigate different physical conditions that lead to hysteresis losses improvement and compare simulation results with high-frequency hysteresis loops [31,36].…”

Functional manganese ferrite/graphene oxide nanocomposites: effects of graphene oxide on the adsorption mechanisms of organic MB dye and inorganic As(v) ions from aqueous solution

“…Details of the synthesis procedures can be found elsewhere. 13,14 The pure MFO nanoparticles and GO nanosheets were used for purposes of comparison with the MFO-GO nanocomposites.…”

“…It was also found that the nitrogen adsorption-desorption isotherm of the MFO-GO nanocomposite displays a type IV curve and H3 hysteresis loop according to the IUPAC (International Union of Pure and Applied Chemistry) classication. 17 The average pore sizes were about 4.2-5.6 nm, which indicated the mesoporous nature of the nanomaterials, [12][13][14][15][16][17][18] which is very promising for adsorption applications.…”

Magnetic hyperthermia behaviour of Co and reduced GO nanocomposites

“…Production of a nanocomposite made of NPs plus reduced graphene oxide (GO) for utilisation in magnetic hyperthermia can improve heating efficiency by enhancement of the active specific surfaces [16, 17]. In one Letter, Yang et al [18] have used iron oxide/graphene nanocomposite for its hyperthermia effects.…”