Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bologna study programme

Options:
  Reset


1 - 10 / 29
First pagePrevious page123Next pageLast page
1.
Saturation magnetisation as an indicator of the disintegration of barium hexaferrite nanoplatelets during the surface functionalisation
Darja 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, original scientific article

Abstract: 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.
Keywords: barium hexaferrite, Fe XANES, EXAFS, magnetic nanoparticles
Published in RUNG: 06.07.2023; Views: 1322; Downloads: 4
.pdf Full text (3,60 MB)
This document has many files! More...

2.
3.
Unravelling the P[sub]3 centers origin in alkali phosphate glasses
Luigi Giacomazzi, Nikita S. Shcheblanov, Layla Martin-Samos, Matjaž Valant, Nadege Ollier, Nicolas Richard, 2021, published scientific conference contribution abstract

Keywords: EPR, DFT, NaPO3, LiPO3, alkali phosphate glasses, point defects
Published in RUNG: 29.09.2021; Views: 1939; Downloads: 7
URL Link to full text
This document has many files! More...

4.
Unravelling the P[sub]3 centers origin in alkali phosphate glasses
Luigi Giacomazzi, Nikita S. Shcheblanov, Layla Martin-Samos, Matjaž Valant, Nadege Ollier, Nicolas Richard, 2021, published scientific conference contribution abstract

Keywords: EPR, DFT, NaPO3, LiPO3, alkali phosphate glasses, point defects
Published in RUNG: 29.09.2021; Views: 1994; Downloads: 0
This document has many files! More...

5.
6.
7.
Vers une connaissance microscopique de la structure de verres de phosphate P2O5
Nicolas Richard, Luigi Giacomazzi, Nikita S. Shcheblanov, Layla Martin-Samos, Nadege Ollier, 2020, popular article

Abstract: Les propriétés d’amplification de la lumière des ions terres rares permettent en les incluant comme dopants dans le cœur des fibres optiques d’obtenir des sources laser et des amplificateurs de lumière compacts. Pour réduire la tendance à l’agrégation des terres rares qui diminuent leurs propriétés amplificatrices, le phosphore est employé comme co-dopant dans ces fibres. Cet article montre comment les méthodes de simulation à l’échelle atomique peuvent aider a' l'optimisation de ce co-dopage en contribuant a' une meilleure comprehension de la structure des verres phosphates [1] et des défauts qui leur sont liés [2]. Au CEA-DAM, ces resultats serviront aussi dans le cadre d'etudes sur le developpement de fibres optiques pour des mesures de dosimetrie radiative.
Keywords: glasses, P2O5, point defects, ab-initio
Published in RUNG: 18.09.2020; Views: 3032; Downloads: 0
This document has many files! More...

8.
v-P[sub]2O[sub]5 "micro-clusters" in P-doped silica studied by a first principles Raman investigation
Luigi Giacomazzi, Layla Martin-Samos, Matjaž Valant, Nicolas Richard, 2019, published scientific conference contribution abstract

Keywords: r-POHC, silica, Raman, first-principles
Published in RUNG: 19.12.2019; Views: 3285; Downloads: 0
This document has many files! More...

9.
10.
Search done in 0.06 sec.
Back to top