Magnetic properties, 57Fe Mössbauer spectroscopy and 1H NMR relaxometry of ε-Fe2-xGaxO3 nanoparticles: The effect of gallium doping on magnetic and MRI performance

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F21%3A00541750" target="_blank" >RIV/68378271:_____/21:00541750 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.jallcom.2020.158187" target="_blank" >https://doi.org/10.1016/j.jallcom.2020.158187</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2020.158187" target="_blank" >10.1016/j.jallcom.2020.158187</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Magnetic properties, 57Fe Mössbauer spectroscopy and 1H NMR relaxometry of ε-Fe2-xGaxO3 nanoparticles: The effect of gallium doping on magnetic and MRI performance

Popis výsledku v původním jazyce

Magnetic nanoparticles of ε-Fe1.76Ga0.24O3 were prepared by thermal treatment of a mesoporous silica matrix impregnated with nitrates. The chosen Ga-doping enhanced magnetization and suppressed the low-temperature spin-reorientation transition typical for ε-Fe2O3. Despite the small mean size of 11 nm, the nanoparticles were in the blocked state over the whole temperature range under study, unlike standard superparamagnetic contrast agents based on other iron oxides or ferrites. The role of Ga-doping in local magnetic properties of the epsilon polymorph of ferric oxide was probed by 57Fe Mössbauer spectroscopy. The particles were further coated with silica and their performance in MRI was tested both in relaxometry and ultra-high-field imaging. The obtained dependences of relaxivity on temperature and thickness of the coating were placed in the context of relevant theoretical models of particle-induced relaxation – motional averaging and static dephasing regimes.

Název v anglickém jazyce

Magnetic properties, 57Fe Mössbauer spectroscopy and 1H NMR relaxometry of ε-Fe2-xGaxO3 nanoparticles: The effect of gallium doping on magnetic and MRI performance

Popis výsledku anglicky

Magnetic nanoparticles of ε-Fe1.76Ga0.24O3 were prepared by thermal treatment of a mesoporous silica matrix impregnated with nitrates. The chosen Ga-doping enhanced magnetization and suppressed the low-temperature spin-reorientation transition typical for ε-Fe2O3. Despite the small mean size of 11 nm, the nanoparticles were in the blocked state over the whole temperature range under study, unlike standard superparamagnetic contrast agents based on other iron oxides or ferrites. The role of Ga-doping in local magnetic properties of the epsilon polymorph of ferric oxide was probed by 57Fe Mössbauer spectroscopy. The particles were further coated with silica and their performance in MRI was tested both in relaxometry and ultra-high-field imaging. The obtained dependences of relaxivity on temperature and thickness of the coating were placed in the context of relevant theoretical models of particle-induced relaxation – motional averaging and static dephasing regimes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

21001 - Nano-materials (production and properties)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Svazek periodika

856

Číslo periodika v rámci svazku

Mar

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

158187

Kód UT WoS článku

000610851500058

EID výsledku v databázi Scopus

2-s2.0-85098159051