On the thermal and hydrothermal stability of spinel iron oxide nanoparticles as single and core-shell hard-soft phases

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F23%3A10458644" target="_blank" >RIV/00216208:11310/23:10458644 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=QerrB69bD2" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=QerrB69bD2</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2023.168909" target="_blank" >10.1016/j.jallcom.2023.168909</a>

Result language

angličtina

Original language name

On the thermal and hydrothermal stability of spinel iron oxide nanoparticles as single and core-shell hard-soft phases

Original language description

The thermal and hydrothermal stability of oleate-capped nanosized spinel iron oxides is of primary importance for the plethora of applications and environments for which they are employed. An in-situ XRD and ex-situ autoclave treatments have been set up for monitoring the thermal and hydrothermal stability in different samples. In detail, spinel iron oxide nanoparticles (NPs) were studied as (i) single-phase alone at three different sizes (about 6, 10, and 15 nm); (ii) as core in a core-shell architecture having cobalt ferrite as shell, at different core sizes (about 6 and 10 nm); (iii) as shell in a core-shell architecture with cobalt ferrite as core, at different shell thicknesses (about 3 and 4 nm). The Rietveld refinement of the diffraction patterns and (57)Fe Mössbauer spectroscopy have been exploited to monitor the evolution of the structural parameters and the hematite fraction. Moreover, transmission electron microscopy has permitted to deepen the morphological details on the phases. The spinel iron oxide-hematite transition has been found size- and time-dependent for the single-phase iron oxide NPs (360-455 °C). The transition temperature has increased significantly when iron oxide is incorporated in a core-shell architecture, both as core (630 °C) and shell (520 °C), suggesting a stabilizing effect of cobalt ferrite. The hydrothermal stability of iron oxide and core-shell NPs has been found dependent on water content, time, and temperature, with a reducing effect of pentanol toward the formation of magnetite from maghemite, highlighted by (57)Fe Mössbauer spectroscopy. The synergic effects of cobalt ferrite and pentanol have limited the formation of hematite, leading to the obtainment of magnetite-covered cobalt ferrite NPs upon the hydrothermal treatment.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Volume of the periodical

940

Issue of the periodical within the volume

April

Country of publishing house

CH - SWITZERLAND

Number of pages

12

Pages from-to

168909

UT code for WoS article

000963143600001

EID of the result in the Scopus database

2-s2.0-85146699388