Influence of synthesis conditions on structural, optical and magnetic properties of iron oxide nanoparticles prepared by hydrothermal method

ABSTRACT

The iron oxide nanoparticles were synthesized by a simple hydrothermal method at different heating temperatures and pH conditions. The synthesized materials were characterized by X-ray diffractometer, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV–visible spectrometer and vibrating sample magnetometer. With increment in pH of the synthesized materials were resulted in orthorhombic (goethite) and cubic (magnetite) structures at pH 6 and 12, respectively. The banding nature of synthesized materials was analyzed by infrared spectra. The synthesized powders at 130 °C showed higher percent of nanorods (length = 90–120 nm) in addition to lower percentage of nanoparticles. The material at pH 12 consisted of maximum nanoparticles with size = 10–60 nm with small agglomerations. Band gap energy of synthesized materials was 2.2–2.8 eV. Herein, the reaction conditions tuned the saturation magnetization (M_S). The maximum M_S (59.38 emu/g) was obtained at pH 12 and lower M_S (0.65 emu/g) was observed at pH 6 due to intrinsic property of goethite phase.

KEYWORDS:

• Hydrothermal temperature
• pH
• magnetite
• goethite
• nanoparticles
• magnetic properties

Acknowledgements

The authors wish to thank Dr M.V. Shankar and Dr B. Vijay Kumar Naidu, Department of Materials Science & NanoTechnology, Y.V. University, Kadapa, for their constant support for providing lab facilities. We are thankful to Dr K.S.V. Krishna Rao, Department of Chemistry, Y.V. University, for allowing in favor of the UV–visible and Fourier transform infrared spectrometer.

Disclosure statement

No potential conflict of interest was reported by authors.