First-principles insights into structure and magnetism in ultra-small tetrahedral iron oxide nanoparticles

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F25%3A00639056" target="_blank" >RIV/68081723:_____/25:00639056 - isvavai.cz</a>

Alternative codes found

RIV/00216224:14310/25:00142964

Result on the web

<a href="https://pubs.rsc.org/en/content/articlelanding/2025/cp/d5cp01415h" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2025/cp/d5cp01415h</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d5cp01415h" target="_blank" >10.1039/d5cp01415h</a>

Result language

angličtina

Original language name

First-principles insights into structure and magnetism in ultra-small tetrahedral iron oxide nanoparticles

Original language description

Structural and magnetic properties of ultra-small tetrahedron-shaped iron oxide nanoparticles were investigated using density functional theory. Tetrahedral and truncated tetrahedral models were considered in both non-functionalized form and with surfaces passivated by pseudo-hydrogen atoms. The focus on these two morphologies reflects their experimental relevance at this size scale and the feasibility of performing fully relaxed, atomistically resolved first-principles simulations. Moreover, a novel application of pseudo-hydrogen passivation to magnetic iron oxide nanoparticles is introduced as a practical strategy to probe intrinsic surface effects on magnetism while reducing artefacts from dangling bonds. Although these terminations are simplified representations, they were found to capture essential aspects affecting nanoparticle behavior. In non-functionalized models, significant distortions due to the undercoordination were observed, including Fe-O bond shortening by up to 0.46 & Aring, and enhanced magnetic moments on oxygen atoms. These changes disrupted ferrimagnetic ordering, with spin-flipping in both tetrahedral and octahedral sublattices leading to an almost 90% reduction in total magnetization. Upon passivation, these effects were largely mitigated: Fe-O bond lengths became more uniform and ferrimagnetic alignment was stabilized as the energetically preferred state. Averaged spin-flip energies were computed to be 58 meV and 72 meV for both geometries, which is markedly lower than values for bulk gamma-Fe2O3 (407-534 meV), suggesting that magnetic disorder may emerge during synthesis at typical growth temperatures. Charge transfer analysis further showed that surface coordination strongly affects electron distribution, with surface capping restoring near bulk-like charge states.

Czech name

—

Czech description

—

Type

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

CEP classification

—

OECD FORD branch

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

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

Name of the periodical

Physical Chemistry Chemical Physics

ISSN

1463-9076

e-ISSN

1463-9084

Volume of the periodical

27

Issue of the periodical within the volume

40

Country of publishing house

GB - UNITED KINGDOM

Number of pages

17

Pages from-to

21424-21440

UT code for WoS article

001566305600001

EID of the result in the Scopus database

2-s2.0-105018694171