Preparation and Study of Zinc Ferrite Nanoparticles with a High Magnetization

Abstract

The zinc-doped maghemite nanoparticles were prepared using ultrasonic radiation. As a precursor, a suspension of maghemite in an alkaline aqueous solution of zinc nitrate at pH = 9 was sonicated. They were investigated by x-ray diffraction, Mössbauer spectroscopy, high-resolution electron microscopy (HREM), and superconducting quantum interference device (SQUID) magnetometry. The results show that by using ultrasound radiation, zinc Zn²⁺ can substitute for Fe³⁺ up to a composition close to zinc ferrite (ZnFe₂O₄), which has a random distribution of Fe³⁺ ions over both A and B sublattices in the spinel structure with an inversity parameter of δ = 0.322. This leads to a maximum saturation magnetization (M _s ) of 64.1 emu/g at 300 K and 73.5 emu/g at 2 K.

Keywords:

• Electron microscopy
• Magnetic measurements
• Sonochemistry
• Synthesis of magnetic nanoparticles
• X-ray diffraction