Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of ε-Fe2O3 phase

Nikolić, Violeta N.; Tadić, Marin; Panjan, Matjaž; Kopanja, Lazar; Cvjetićanin, Nikola; Spasojević, Vojislav

doi:10.1016/j.ceramint.2016.11.132

Cited by 44 publications

(38 citation statements)

References 80 publications

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“…: 16-653) is presented in small amount. Figure 2 presents hysteresis of the same sample [59]. Although the sample showed a higher amount of the α-Fe 2 O 3 phase, measured critical field achieved a value characteristic for ε-Fe 2 O 3 phase: 14.1 kOe (Figure 2) [59].…”

Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 93%

“…Observed behavior of measured critical field of the sample has been attributed to the completion of an ε-Fe 2 O 3 → α-Fe 2 O 3 phase transformation [59]; thus the presence of the only one phase-α-Fe 2 O 3 phase-at 1060°C would be expected. With the aim to check the concluded remark regarding the completion of ε-Fe 2 O 3 → α-Fe 2 O 3 phase transformation at depicted temperature, investigation presented in Ref.…”

Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 94%

“…The increase of the annealing temperature for only 10°C (T ann = 1060°C, t ann = 3 h) resulted in the sharp decrease of H meas (2300 Oe), which is shown in Figure 2(a) [59].…”

Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 96%

“…The auto-catalyzed sol-gel synthesis implied the dissolving of iron (III) nitrate nonahydrate (Fe(NO 3 ) 3 × 9H 2 O) in water in molar ratio 0.013:1 (catalyst solution), while mixing of tetraethyl orthosilicate (TEOS), ethanol (C 2 H 5 OH), and water in molar proportion 1:12:12 enabled formation of alkoxide solution [59]. Solutions were mixed and stirred at room temperature.…”

Section: Nano-hematite-based Materials Prepared By Auto-catalyzed Solmentioning

confidence: 99%

“…Variation of the annealing conditions enables observation of the changes in the H crit of the prepared samples, which is in detail discussed in Ref. [59].…”

Section: Nano-hematite-based Materials Prepared By Auto-catalyzed Solmentioning

confidence: 99%

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Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Nikolić¹

2019

Mineralogy [Working Title]

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The scope of this chapter is to get deeper insight into the correlation between synthesis parameters and magnetic behavior of the nanocomposite materials containing hematite (α-Fe 2 O 3 ) nanoparticles. Potential applications of nanohematite in biomedicine are listed in the short overview. Then, basic requirements necessary for synthesis of high-quality nanoparticles for biomedical application are summarized. The next part of the chapter is devoted to the sol-gel synthesis that is recognized as suitable for preparation of the nanocomposite materials containing α-Fe 2 O 3 nanoparticles. Having in mind that sol-gel method considers preparation of hematite nanoparticles via Fe 2 O 3 phase transformations initiated by thermal treatment at high temperatures, coexistence of the other iron oxides (such as ε-Fe 2 O 3 ) with α-Fe 2 O 3 phase is commented. Special attention is paid on mechanism of the critical field (which is in literature usually denoted as coercivity field) alterations. Diffraction patterns and hysteresis measurements of the chosen samples containing hematite nanoparticles in the silica matrix are represented. Finally, variations in the observed measured critical field values are discussed.

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Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 93%

Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 94%

“…The increase of the annealing temperature for only 10°C (T ann = 1060°C, t ann = 3 h) resulted in the sharp decrease of H meas (2300 Oe), which is shown in Figure 2(a) [59].…”

Section: Variation Of the Sol-gel Synthesis Conditions: Alteration Ofmentioning

confidence: 96%

Section: Nano-hematite-based Materials Prepared By Auto-catalyzed Solmentioning

confidence: 99%

“…Variation of the annealing conditions enables observation of the changes in the H crit of the prepared samples, which is in detail discussed in Ref. [59].…”

Section: Nano-hematite-based Materials Prepared By Auto-catalyzed Solmentioning

confidence: 99%

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Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Nikolić¹

2019

Mineralogy [Working Title]

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Rising Like a Phoenix from the Ashes: Fire‐Proof Magnetically Retrievable Supraparticles with an Optical Fingerprint for Postmortem Identification of Products

Miller

Wenderoth

Wintzheimer

et al. 2022

Advanced Optical Materials

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correctly and rarely meet the required safety standards. [1,2] Frequently, counterfeit components cause a short circuit, overheat, and subsequently catch fire. Manufacturers are liable in such a scenario and face an enormous reputational loss unless they can prove forgery. This topic is highly relevant for forward-looking industries such as electromobility and automatization, since counterfeit battery cells, for example, can result in vehicle fires.Fire-proof postmortem labels could, for example, enable publicly appointed and sworn experts to verify the originality of a product even after a fire. To our knowledge, however, there are currently no suitable marking technologies available to prove beyond doubt the originality of an object after a fire.In forensic science, comprehensive analytical methods have been applied and further developed to characterize fire debris. Examples include gas chromatography coupled with a mass spectrometry detector, [3][4][5] isotopic ratio mass spectrometry, [6,7] capillary electrophoresis, [8][9][10] or vibrational spectroscopic analysis methods, such as Raman or infrared spectroscopy. [11][12][13] All established methods for the characterization of fire residues have in common that they are complicated, as well as time-and cost-intensive, since also partly complex extraction steps of the analyte are necessary. Moreover, they are based exclusively on the analysis of the intrinsic material properties of burned objects, which, however, can change considerably and manifold depending on the fire condition. [14] Conventional anticounterfeiting features, such as miniaturized printed watermarks or quick response (QR) codes, as well as radio-frequency Identification (RFID) chips, show a sufficient performance during the useful life of a product but are unsuitable for postmortem identification as they are to a large extent not fire-proof. There have been attempts to coat RFID chips with anti-fire materials to increase their resistance when exposed to fire. However, tests were successful only up to 250 °C and the tags are limited in that their components decompose thermally above temperatures beyond ≈500 °C. [15] In addition, these tags are in the macroscopic size range and are not suitable for marking components of electronic devices (e.g., microchips).For these reasons, novel approaches are needed to verify the originality of burned electronic devices. Within the last Counterfeit electronic products not only cause financial losses but also come with safety risks. The worst-case failure scenario certainly is a fire event. Since manufacturers are liable for damages and suffer image loss, fire-proof postmortem taggants are needed, enabling differentiation between originals and counterfeits even after a fire incident. This work presents such taggants: optomagnetic supraparticles (SPs), i.e., complex microscale particles composed of luminescent and magnetic nanoparticles (NPs) are generated. Their hybrid nature is pivotal, as magnetic separation can effectively remove the tags from light-absorb...

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Simple Fabrication of ϵ‐Fe₂O₃ Nanoparticles Containing Silica Monoliths with Enhanced Coercivity

et al. 2022

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Most of large-size permanent room-temperature hard magnets contain rare-earth elements. Here, we present the preparation of a large-size rare-earth free hard magnet based on the loading of the ordered mesoporosity of a preformed ordered mesoporous silica monolith obtained by a sol-gel route with the Fe(NO 3 ) 3 salt, followed by a simple calcination in air. The investigation of the influence of the thermal treatment temperature as well as the Fe/Si ratio on the microstructure of the ɛ-Fe 2 O 3 /SiO 2 nanocomposites reveals well-controlled ɛ-Fe 2 O 3 particles size and size distribution. Their magnetic study allows us i) to specify the size of the particles with an enhanced coercivity and ii) to show a linear correlation between the magnetic coercivity of the materials and the mass percent of these particles in the nanocomposites. A ɛ-Fe 2 O 3 based bulk hard magnet with the highest coercive field of 18 kOe at room temperature was obtained by this synthesis process.

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Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of ε-Fe2O3 phase

Cited by 44 publications

References 80 publications

Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Rising Like a Phoenix from the Ashes: Fire‐Proof Magnetically Retrievable Supraparticles with an Optical Fingerprint for Postmortem Identification of Products

Simple Fabrication of ϵ‐Fe₂O₃ Nanoparticles Containing Silica Monoliths with Enhanced Coercivity

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Influence of annealing treatment on magnetic properties of Fe2O3/SiO2 and formation of ε-Fe2O3 phase

Cited by 44 publications

References 80 publications

Preparation and Characterization of Fe2O3-SiO2 Nanocomposite for Biomedical Application

Preparation and Characterization of Fe2O3-SiO2 Nanocomposite for Biomedical Application

Rising Like a Phoenix from the Ashes: Fire‐Proof Magnetically Retrievable Supraparticles with an Optical Fingerprint for Postmortem Identification of Products

Simple Fabrication of ϵ‐Fe2O3 Nanoparticles Containing Silica Monoliths with Enhanced Coercivity

Contact Info

Product

Resources

About

Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Preparation and Characterization of Fe₂O₃-SiO₂ Nanocomposite for Biomedical Application

Simple Fabrication of ϵ‐Fe₂O₃ Nanoparticles Containing Silica Monoliths with Enhanced Coercivity