Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite?
Today, magnetic nanoparticles are present in multiple medical and industrial applications. We take a closer look at the synthesis of magnetic iron oxide nanoparticles through the co-precipitation of iron salts in an alkaline environment. The variation of the synthesis parameters (ion concentration,...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-03-01
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| Series: | Crystals |
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| Online Access: | https://www.mdpi.com/2073-4352/10/3/214 |
| _version_ | 1811303660864405504 |
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| author | Sebastian P. Schwaminger Christopher Syhr Sonja Berensmeier |
| author_facet | Sebastian P. Schwaminger Christopher Syhr Sonja Berensmeier |
| author_sort | Sebastian P. Schwaminger |
| collection | DOAJ |
| description | Today, magnetic nanoparticles are present in multiple medical and industrial applications. We take a closer look at the synthesis of magnetic iron oxide nanoparticles through the co-precipitation of iron salts in an alkaline environment. The variation of the synthesis parameters (ion concentration, temperature, stirring rate, reaction time and dosing rate) change the structure and diameter of the nanoparticles. Magnetic iron oxide nanoparticles are characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM). Magnetic nanoparticles ranging from 5 to 16 nm in diameter were synthesized and their chemical structure was identified. Due to the evaluation of Raman spectra, TEM and XRD, the magnetite and maghemite nanoparticles can be observed and the proportion of phases and the particle size can be related to the synthesis conditions. We want to highlight the use of Raman active modes A<sub>1g</sub> of spinel structured iron oxides to determine the content of magnetite and maghemite in our samples. Magnetite nanoparticles can be derived from highly alkaline conditions even without establishing an inert atmosphere during the synthesis. The correlation between the particle properties and the various parameters of the synthesis was modelled with linear mixture models. The two models can predict the particle size and the oxidation state of the synthesized nanoparticles, respectively. The modeling of synthesis parameters not only helps to improve synthesis conditions for iron oxide nanoparticles but to understand crystallization of nanomaterials. |
| first_indexed | 2024-04-13T07:52:03Z |
| format | Article |
| id | doaj.art-0bbc253609344ace915a6f6f5abd0bd5 |
| institution | Directory Open Access Journal |
| issn | 2073-4352 |
| language | English |
| last_indexed | 2024-04-13T07:52:03Z |
| publishDate | 2020-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Crystals |
| spelling | doaj.art-0bbc253609344ace915a6f6f5abd0bd52022-12-22T02:55:30ZengMDPI AGCrystals2073-43522020-03-0110321410.3390/cryst10030214cryst10030214Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite?Sebastian P. Schwaminger0Christopher Syhr1Sonja Berensmeier2Bioseparation Engineering Group, Department of Mechanical Engineering, Technical University of Munich, 85748 Garching, GermanyBioseparation Engineering Group, Department of Mechanical Engineering, Technical University of Munich, 85748 Garching, GermanyBioseparation Engineering Group, Department of Mechanical Engineering, Technical University of Munich, 85748 Garching, GermanyToday, magnetic nanoparticles are present in multiple medical and industrial applications. We take a closer look at the synthesis of magnetic iron oxide nanoparticles through the co-precipitation of iron salts in an alkaline environment. The variation of the synthesis parameters (ion concentration, temperature, stirring rate, reaction time and dosing rate) change the structure and diameter of the nanoparticles. Magnetic iron oxide nanoparticles are characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM). Magnetic nanoparticles ranging from 5 to 16 nm in diameter were synthesized and their chemical structure was identified. Due to the evaluation of Raman spectra, TEM and XRD, the magnetite and maghemite nanoparticles can be observed and the proportion of phases and the particle size can be related to the synthesis conditions. We want to highlight the use of Raman active modes A<sub>1g</sub> of spinel structured iron oxides to determine the content of magnetite and maghemite in our samples. Magnetite nanoparticles can be derived from highly alkaline conditions even without establishing an inert atmosphere during the synthesis. The correlation between the particle properties and the various parameters of the synthesis was modelled with linear mixture models. The two models can predict the particle size and the oxidation state of the synthesized nanoparticles, respectively. The modeling of synthesis parameters not only helps to improve synthesis conditions for iron oxide nanoparticles but to understand crystallization of nanomaterials.https://www.mdpi.com/2073-4352/10/3/214iron oxide nanoparticlesco-precipitationsynthesismagnetic nanoparticlesx-ray diffractionraman spectroscopytransmission electron microscopydesign of experiments |
| spellingShingle | Sebastian P. Schwaminger Christopher Syhr Sonja Berensmeier Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? Crystals iron oxide nanoparticles co-precipitation synthesis magnetic nanoparticles x-ray diffraction raman spectroscopy transmission electron microscopy design of experiments |
| title | Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? |
| title_full | Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? |
| title_fullStr | Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? |
| title_full_unstemmed | Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? |
| title_short | Controlled Synthesis of Magnetic Iron Oxide Nanoparticles: Magnetite or Maghemite? |
| title_sort | controlled synthesis of magnetic iron oxide nanoparticles magnetite or maghemite |
| topic | iron oxide nanoparticles co-precipitation synthesis magnetic nanoparticles x-ray diffraction raman spectroscopy transmission electron microscopy design of experiments |
| url | https://www.mdpi.com/2073-4352/10/3/214 |
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