Investigation of the structural, magnetic and dielectric properties of NiFe2O4/nanoclay composites synthesized via sol-gel autocombustion

Abstract

NiFe2O4 nanoparticles supported with 0, 2, 4, and 6 wt% of dodecylalkylammonium intercalated montmorillonite (DDA-MMT) are synthesized by sol-gel autocombustion method. The structural and morphological properties have been analyzed by XRD, FTIR and SEM techniques. The dielectric, magnetic, optical and electrical properties of the prepared samples have been evaluated. XRD analysis confirmed the formation of MMT layers exfoliated NiFe2O4 nanoparticles by showing the absence of 001 reflection of DDA-MMT in NiFe2O4/DDA-MMT compounds. The crystallite size is determined to be 31.32 nm for naked Ni ferrite and decreases with increase of DDA-MMT content, which revealed crystallization of NiFe2O4 is influenced by DDA-MMT. The saturation magnetization of Ni ferrite is found to be increased from 29.84 emu/g to the range of 30.78–38.45 emu/g when supported with DDA-MMT up to 6 wt%. A significant enhancement of dielectric constant, from 2.7 to 4.2, is observed when Ni ferrite is supported with 2 wt% DDA-MMT which could be accounted for interfacial polarization between MMT layers and ferrite nanoparticles. Optical band gap increases from 1.67 to 1.76 eV with application of 2 wt% DDA-MMT as supporting material in Ni ferrite. Present work indicates that the magnetic, dielectric, optical as well as electrical properties of Ni ferrite nanomaterial may be modified by adding the right quantity of DDA-MMT as a supporting material, which will ultimately assist in broadening the uses of Ni ferrite.

Keywords

• Ferrite/nanoclay
• Sol-gel autocombustion method
• X-ray diffraction
• FTIR
• Dielectric constant