Structural, Magnetic, and AC Measurements of Nanoferrites/Graphene Composites.

Shaimaa A Habib,Mayeen U Khandaker,Di Zhou,Mohammad A Islam,Hamidreza Mohafez,Sergei V Trukhanov,Samia A Saafan,Moustafa A Darwish,Maha K Omar,Alex V Trukhanov,Talaat M Meaz

doi:10.3390/nano12060931

Abstract

As a contribution to the graphene-based nanoferrite composites, this article is intended to present Mn, Co, and Co-Mn nanoferrites for the preparation and investigation of such samples. Nanoparticles of Co ferrite, Mn ferrite, and Co-Mn ferrite were chemically synthesized by the coprecipitation method. The composites of ferrite/graphene were made by incorporating weight ratios of 25% graphene to 75% ferrite. Various structural and characterizing investigations of ferrite samples and ferrite/graphene composites were performed, including XRD, EDX, SEM, VSM hysteresis loops, AC conductivity, and dielectric behavior. The investigations ensured the formation of the intended nanoferrite powders, each having a single-phase crystal structure with no undesired phases or elements. All samples exhibit a soft magnetic behavior. They show a semiconducting behavior of AC electrical conductivity as well. This was proved by the temperature dependence of the AC’s electrical conductivity. Whereas the dielectric function and loss tangent show an expected, well-explained behavior, the ferrite/graphene composite samples have lower saturation magnetization values, lower AC conductivity, and dielectric constant values than the pure ferrites but still have the same behavior trends as those of the pure ferrites. The values obtained may represent steps on developing new materials for expected applications, such as manufacturing supercapacitors and/or improved battery electrodes.

Highlights

Europe SE, Neu-Isenburg, Germany), energy dispersive X-ray (EDX) (Oxford Instruments, Moscow, Russia), scanning electron microscopy (SEM) (Lyra3, Tescan, Brno, Czech Republic), and vibrating sample magnetometer (VSM) (Criogenic Ltd., London, United Kingdom) measurements, and some other amounts were pressed into small pellets for electrical measurements
CoFe2 O4, MnFe2 O4, and Co0.5 Mn0.5 Fe2 O4 nanosized particles were successfully synthesized by the coprecipitation method, and their composites with graphene were prepared with mixing weight ratios of 75% ferrite to 25% graphene
The average particle sizes of ferrite nanoparticles calculated from the XRD are in strong agreement with those calculated from the SEM images

Summary

Introduction

Over the last few decades, the global need for energy has skyrocketed. Nonrenewable fossil fuels, whose reserves will deplete in the future, account for the majority of the increase in global energy use, not to mention that those sources are not environmentally friendly. New energy systems utilizing renewable energy sources are urgently required. For electric automobiles and other extensively utilized energy storage devices, there are many materials, so science researchers are working on new battery and supercapacitor technologies [1]. Supercapacitors have a distinct role in current technology because they bridge the gap between batteries and ordinary capacitors by providing stored energy quickly and effectively [2]. While Li-ion batteries are already widely used in electric devices and cars, the need for new battery technologies beyond Li-ion batteries has drawn the scientific community’s attention

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Conclusion