Ni-Zn Ferrite-graphene Nanohybrids: Synthesis and Characterization of Magnetic and Microwave Absorbing Properties

¹ Department of Mechanical, Materials and Manufacturing Engineering, The University of Nottingham Malaysia, Jalan Broga 43500 Semenyih, Selangor, Malaysia
² Faculty of Applied Science and Foundation Studies, Infrastructure University Kuala Lumpur Unipark Suria, Jalan Ikram-Uniten, 43000 Kajang, Selangor, Malaysia.

^a Corresponding author: ing.kong@nottingham.edu.my

Abstract

An in-situ deposition technique was used in the synthesis of Ni-Zn ferrite-graphene (NZFG) nanohybrids. The XRD patterns revealed the presence of cubic spinel structure of Ni-Zn ferrite (NZF) nanoparticles with good crystallinity and small crystallite sizes. The SEM images showed NZF nanoparticles were uniformly deposited on graphene sheets. The effect of different loading amounts of NZF nanoparticles in the nanohybrids was also investigated by tuning the mass ratio of FeCl₃ and expanded graphite (EG). The magnetic measurements showed ferromagnetic behaviour with low coercivity. Improvements in saturation magnetization of the nanohybrids can be seen with increasing mass ratio of FeCl₃:EG. The microwave absorption properties were determined based on the measured relative complex permittivity and permeability. For the nanohybrids, the minimum reflection loss (R_L) obtained is -37.57 dB at 7.54 GHz and the absorbing bandwidth in which the R_L is less than -10 dB is 7.30 GHz when the NZF content was 79 wt·% at 7 mm thickness. The enhancement in the minimum R_L was due to the synergistic effect between NZF nanoparticles and graphene.