| People | Locations | Statistics |
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| Naji, M. |
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| Motta, Antonella |
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| Aletan, Dirar |
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| Mohamed, Tarek |
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| Ertürk, Emre |
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| Taccardi, Nicola |
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| Kononenko, Denys |
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| Petrov, R. H. | Madrid |
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| Alshaaer, Mazen | Brussels |
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| Bih, L. |
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| Casati, R. |
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| Muller, Hermance |
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| Kočí, Jan | Prague |
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| Šuljagić, Marija |
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| Kalteremidou, Kalliopi-Artemi | Brussels |
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| Azam, Siraj |
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| Ospanova, Alyiya |
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| Blanpain, Bart |
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| Ali, M. A. |
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| Popa, V. |
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| Rančić, M. |
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| Ollier, Nadège |
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| Azevedo, Nuno Monteiro |
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| Landes, Michael |
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| Rignanese, Gian-Marco |
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Gjørup, Frederik Holm
Aarhus University
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (17/17 displayed)
- 2024Aligned Permanent Magnet Made in Seconds–An In Situ Diffraction Studycitations
- 2024High-performance hexaferrite magnets tailored through alignment of shape-controlled nanocompositescitations
- 2023High-Performance Hexaferrite Ceramic Magnets Made from Nanoplatelets of Ferrihydrite by High-Temperature Calcination for Permanent Magnet Applicationscitations
- 2023Sintering in seconds, elucidated by millisecond in situ diffractioncitations
- 2022Understanding the Compaction of Nanopowders Through Neutron and X-ray Diffraction
- 2022Synthesis of Phase-Pure Thermochromic VO2 (M1)citations
- 2021‘Need for Speed’: Sub-second in situ diffraction to unravel rapid sintering & texture evolution in ferrite magnets
- 2021‘Need for Speed’: Sub-second in situ diffraction to unravel rapid sintering & texture evolution in ferrite magnets
- 2021Getting the most out of neutron powder diffraction
- 2020Exploring the direct synthesis of exchange-spring nanocomposites by reduction of CoFe 2 O 4 spinel nanoparticles using in situ neutron diffractioncitations
- 2020Exploring the direct synthesis of exchange-spring nanocomposites by reduction of CoFe2O4 spinel nanoparticles using in situ neutron diffractioncitations
- 2019Novel fast heating furnaces for in situ powder neutron diffraction
- 2019Novel in situ powder neutron diffraction setups – The creation of a modern magnetic compound
- 2019In Situ In-House Powder X-ray Diffraction Study of Zero-Valent Copper Formation in Supercritical Methanolcitations
- 2019In Situ In-House Powder X-ray Diffraction Study of Zero-Valent Copper Formation in Supercritical Methanolcitations
- 2019Laboratory setup for rapid in situ powder X-ray diffraction elucidating Ni particle formation in supercritical methanolcitations
- 2018Coercivity enhancement of strontium hexaferrite nano-crystallites through morphology controlled annealingcitations
Places of action
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article
Coercivity enhancement of strontium hexaferrite nano-crystallites through morphology controlled annealing
Abstract
In order to improve the performance of ferrite based permanent magnet materials, the evolution of magnetic properties with increasing particle size of anisotropic SrFe12O19 nano-platelets is investigated, allowing elucidation of the stable single domain (SSD) size. Phase-pure, ultra-thin platelet-shaped strontium hexaferrite (SrFe12O19) nano-crystallites have been successfully synthesized using a simple, green and scalable supercritical hydrothermal flow method. The flow reactor precursor is prepared from aqueous solutions of strontium nitrate, iron nitrate and sodium hydroxide. The samples were subsequently annealed at different temperatures (600–1100 °C) in intervals between 1 and 68 h in order to tune size and morphology. The nano-platelets grow anisotropically, with pronounced growth along the c-axis, which coincides with the magnetic easy axis. The annealing treatment gives rise to variations in platelet aspect ratio. Microstructural investigations by transmission electron microscopy (TEM) and Rietveld refinement of powder X-ray diffraction (PXRD) data, combined with vibrating sample magnetometry (VSM), reveal a significant correlation between size and morphology, on the macroscopic magnetic properties of the produced powders. The optimal single-domain crystallite dimensions are found from PXRD to be 62 nm thick and 76 nm wide, attaining a coercivity (Hc) of 459(10) kA/m (5.77 kOe), and a saturation magnetization (Ms) of 74.0(1) Am2/kg. A theoretical single domain critical size for SrFe12O19 particles is proposed, based on a disc-shaped ellipsoidal particle model in combination with the obtained experimental results. Particle shape is revealed to have an enormous influence on the SSD size, varying significantly for anisotropic particles compared to isotropic particles, and thus underlying the need for meticulous characterization in order to optimize the magnetic performance of specific systems.