<abstract xmlns="http://www.w3.org/1999/xhtml">Using the sol-gel method we synthesized hematite (<italic>α</italic> − Fe2O3) nanoparticles in a silica matrix with 60 wt % of hematite. X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra of the sample demonstrate the formation of the <italic>α</italic> − Fe2O3 phase and amorphous silica. A transmission electron microscopy (TEM) measurements show that the sample consists of two particle size distributions of the hematite nanoparticles with average sizes around 10 nm and 20 nm, respectively. Magnetic properties of hematite nanoparticles were measured using a superconducting quantum interference device (SQUID). Investigation of the magnetic properties of hematite nanoparticles showed a divergence between field-cooled (FC) and zero-field-cooled (ZFC) magnetization curves and two maxima. The ZFC magnetization curves displayed a maximum at around <italic>T</italic>B = 50 K (blocking temperature) and at <italic>T</italic>M = 83 K (the Morin transition). The hysteresis loop measured at 5 K was symmetric around the origin, with the values of coercivity, remanent and mass saturation magnetization <italic>H</italic>C10K ≈ 646 A/cm, (810 Oe), <italic>M</italic>r10K = 1.34 emu/g and <italic>M</italic>S10K = 6.1 emu/g respectively. The absence of both coercivity (<italic>H</italic>C300K = 0) and remanent magnetization (<italic>M</italic>r300K = 0) in <italic>M</italic>(<italic>H</italic>) curve at 300 K reveals super-paramagnetic behavior, which is desirable for application in biomedicine. The bimodal particle size distributions were used to describe observed magnetic properties of hematite nanoparticles. The size distribution directly influences the magnetic properties of the sample.</abstract>

Using the sol-gel method we synthesized hematite (α − Fe2O3) nanoparticles in a silica matrix with 60 wt % of hematite. X-ray diffraction (XRD) patterns and Fourier transform infrared (FTIR) spectra of the sample demonstrate the formation of the α − Fe2O3 phase and amorphous silica. A transmission electron microscopy (TEM) measurements show that the sample consists of two particle size distributions of the hematite nanoparticles with average sizes around 10 nm and 20 nm, respectively. Magnetic properties of hematite nanoparticles were measured using a superconducting quantum interference device (SQUID). Investigation of the magnetic properties of hematite nanoparticles showed a divergence between field-cooled (FC) and zero-field-cooled (ZFC) magnetization curves and two maxima. The ZFC magnetization curves displayed a maximum at around TB = 50 K (blocking temperature) and at TM = 83 K (the Morin transition). The hysteresis loop measured at 5 K was symmetric around the origin, with the values of coercivity, remanent and mass saturation magnetization HC10K ≈ 646 A/cm, (810 Oe), Mr10K = 1.34 emu/g and MS10K = 6.1 emu/g respectively. The absence of both coercivity (HC300K = 0) and remanent magnetization (Mr300K = 0) in M(H) curve at 300 K reveals super-paramagnetic behavior, which is desirable for application in biomedicine. The bimodal particle size distributions were used to describe observed magnetic properties of hematite nanoparticles. The size distribution directly influences the magnetic properties of the sample.

Magnetic properties of hematite (<italic>α</italic> − Fe2O3) nanoparticles synthesized by sol-gel synthesis method: The influence of particle size and particle size distribution

Institute for Mother and Child Healthcare of Serbia

Institute of Medical Physics, Biophysics, Informatics and Telemedicine, Faculty of Medicine

Faculty of Mathematics and Computer Science

Journal of Electrical Engineering

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Magnetic properties of hematite ( − FeO) nanoparticles synthesized by sol-gel synthesis method: The influence of particle size and particle size distribution

Using the sol-gel method we synthesized hematite (α − Fe2O3) nanoparticles in a silica matrix with 60 wt % of hematite. X-ray diffraction (XRD) patterns and...

Magnetic properties of hematite (α − Fe₂O₃) nanoparticles synthesized by sol-gel synthesis method: The influence of particle size and particle size distribution

Published Online: Sep 28, 2019

Page range: 71 - 76

Received: Mar 19, 2019

DOI: https://doi.org/10.2478/jee-2019-0044

Keywords
iron oxide, hematite ( − FeO), sol-gel synthesis, superparamagnetism (SPION), Morin transition, particle size effects

© 2019 Marin Tadic et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Magnetic properties of hematite (α − Fe2O3) nanoparticles synthesized by sol-gel synthesis method: The influence of particle size and particle size distribution

Published Online: Sep 28, 2019

Page range: 71 - 76

Received: Mar 19, 2019

DOI: https://doi.org/10.2478/jee-2019-0044

Keywordsiron oxide, hematite ( − FeO), sol-gel synthesis, superparamagnetism (SPION), Morin transition, particle size effects

© 2019 Marin Tadic et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Magnetic properties of hematite (α − Fe₂O₃) nanoparticles synthesized by sol-gel synthesis method: The influence of particle size and particle size distribution

Keywords
iron oxide, hematite ( − FeO), sol-gel synthesis, superparamagnetism (SPION), Morin transition, particle size effects