1. Saturation magnetisation as an indicator of the disintegration of barium hexaferrite nanoplatelets during the surface functionalisationDarja Lisjak, Iztok Arčon, Matic Poberžnik, Gabriela Herrero‑Saboya, Ali Tufani, Andraž Mavrič, Matjaž Valant, Patricija Hribar Boštjančič, Alenka Mertelj, Darko Makovec, Layla Martin‑Samos, 2023, izvirni znanstveni članek Opis: Barium hexaferrite nanoplatelets (BHF NPLs) are permanent nanomagnets with the magnetic easy axis aligned perpendicular to their basal plane. By combining this specific property with optimised surface chemistry, novel functional materials were developed, e.g., ferromagnetic ferrofluids and porous nanomagnets. We compared the interaction of chemically different phosphonic acids, hydrophobic and hydrophilic with 1–4 phosphonic groups, with BHF NPLs. A decrease in the saturation magnetisation after functionalising the BHF NPLs was correlated with the mass fraction of the nonmagnetic coating, whereas the saturation magnetisation of the NPLs coated with a tetraphosphonic acid at 80 °C was significantly lower than expected. We showed that such a substantial decrease in the saturation magnetisation originates from the disintegration of BHF NPLs, which was observed with atomic-resolution scanning transmission electron microscopy and confirmed by a computational study based on state-of-the-art first-principles calculations. Fe K-edge XANES (X-ray absorption near-edge structure) and EXAFS (Extended X-ray absorption fine structure) combined with Fourier-transformed infrared (FTIR) spectroscopy confirmed the formation of an Fe–phosphonate complex on the partly decomposed NPLs. Comparing our results with other functionalised magnetic nanoparticles confirmed that saturation magnetisation can be exploited to identify the disintegration of magnetic nanoparticles when insoluble disintegration products are formed. Ključne besede: barium hexaferrite, Fe XANES, EXAFS, magnetic nanoparticles Objavljeno v RUNG: 06.07.2023; Ogledov: 1262; Prenosov: 4 Celotno besedilo (3,60 MB) Gradivo ima več datotek! Več... |
2. Magnetic anisotropy of strontium ferrite nanoparticlesCesar de Julian Fernandez, D. Mishra, M. Cabassi, M. Petrecca, M. Albino, M. Suara-Muzquiz, Petra Jenuš, A. Quesada, T. Schliesch, Blaž Belec, C. Sangregorio, F. Albertini, 2019, objavljeni povzetek znanstvenega prispevka na konferenci Ključne besede: hexaferrite, nanoparticles, magnetic anisotropy, SPD Objavljeno v RUNG: 04.06.2019; Ogledov: 3614; Prenosov: 0 Gradivo ima več datotek! Več... |
3. Incorporation of Sc into the structure of barium-hexaferrite nanoplatelets and its ex-traordinary finite-size effect on the magnetic propertiesDarko Makovec, Matej Komelj, Goran Dražić, Blaž Belec, Tanja Goršak, Sašo Gyergyek, Darja lisjak, 2019, izvirni znanstveni članek Ključne besede: Nanoparticles, Magnetic properties, Size effect, Structure properties relationship, Ferrite. Objavljeno v RUNG: 06.05.2019; Ogledov: 3253; Prenosov: 0 Gradivo ima več datotek! Več... |
4. |
5. |
6. |
7. Bi-magnetic composite nanoplatelets combining hard-magnetic barium hexaferrite core covered with soft magnetic iron oxide layerBlaž Belec, Darko Makovec, Goran Dražić, Benjamin Podmiljšak, Tanja Goršak, Sašo Gyergek, Matej Komelj, Josep Nogues, vabljeno predavanje na konferenci brez natisa Ključne besede: bi-magnetic nanoparticles, composite nanoparticles, exchange coupling Objavljeno v RUNG: 05.06.2018; Ogledov: 3865; Prenosov: 0 Gradivo ima več datotek! Več... |
8. |