# Microwave Hydrothermal Synthesis of Nanoscale CoFe2O4 and Regulation of Its Morphology and Properties

## TL;DR

This paper explores a new microwave hydrothermal method to control the shape and performance of CoFe2O4 nanoparticles for better magnetic and wave-absorbing properties.

## Contribution

A novel microwave hydrothermal synthesis method is introduced to regulate CoFe2O4 morphology and properties under mild conditions.

## Key findings

- CoFe2O4 samples synthesized at 75 °C for 30 min show strong wave-absorbing performance with a minimum reflection loss below −30 dB.
- Samples treated at 100 °C for 15 min exhibit improved magnetic properties with saturation magnetization near 60 emu/g.

## Abstract

As a ferrite material with excellent magnetic and dielectric properties, CoFe2O4 is in high demand for applications in areas such as wave absorption and magnetic storage. Effective regulation of its nanoscale morphology is central to improving application performance. Conventional synthesis methods often face challenges including poor particle dispersion and irregular morphology, which limit further optimization of material properties. In this study, a combined approach of microwave hydrothermal synthesis and annealing was employed to systematically investigate the effects of hydrothermal temperature, reaction time, and annealing parameters on the morphology and properties of CoFe2O4. The samples were characterized using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and other techniques. Experimental results show that process parameters exert a notable influence on the crystallinity, particle dispersibility, magnetic and wave-absorbing properties of CoFe2O4: the sample prepared by microwave hydrothermal treatment at 75 °C for 30 min exhibits relatively better wave-absorbing performance, with a minimum reflection loss of less than −30 dB and an effective absorption bandwidth covering 8~16 GHz; the sample treated at 100 °C for 15 min shows a more balanced magnetic performance, with the saturation magnetization approaching 60 emu/g. The quantitative structure–property relationships of pure-phase CoFe2O4 across microwave hydrothermal and post-annealing processes, and achieve stable, reproducible performance enhancements under optimized mild conditions. These results supplement key experimental data for the low-temperature preparation of CoFe2O4 and establish a practical, energy-efficient parameter framework for future structural design and process optimization of this important magnetic material.