Activation of NdFeB magnetic material upon exposure to oxygen plasma

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28610%2F25%3A63595763" target="_blank" >RIV/70883521:28610/25:63595763 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0169433225020550" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0169433225020550</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.apsusc.2025.164339" target="_blank" >10.1016/j.apsusc.2025.164339</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Activation of NdFeB magnetic material upon exposure to oxygen plasma

Popis výsledku v původním jazyce

In bonded NdFeB magnets, the fillers’ adhesion in the polymer matrix of composites is often insufficient, necessitating filler wettability modification before mixing with liquid polymers. Inductively coupled radiofrequency oxygen plasma was used to modify the surface wettability of commercial NdFeB flakes. A pronounced minimum in water contact angle (WCA) was observed after approximately 100 ms of treatment in plasma (50 Pa, 500 W). A deeper minimum was observed upon treatment in the flowing afterglow. The flux of oxygen atoms on the NdFeB flakes’ surface was ∼3 × 1023 m−2 s−1, and the WCA below 20° was observed after treating the samples in the afterglow for 0.05–0.5 s; corresponding O-atom doses 1022–1023 m−2. Larger doses caused a gradual loss of hydrophilicity, and an initial WCA of ∼75° was established after treating the samples in the afterglow for ∼40 s. This was attributed to the segregation and oxidation of iron on the NdFeB surface. Thorough XPS depth profiling revealed oxidation kinetics. The treatment in the glowing plasma caused a similar evolution, except that hydrophobicity was re-established after 1-s plasma treatment. The segregation of iron on the surface caused the formation of Fe2O3, and the intermediate layer toward the bulk consisted of Nd2O3 dispersed in the Fe matrix.

Název v anglickém jazyce

Activation of NdFeB magnetic material upon exposure to oxygen plasma

Popis výsledku anglicky

In bonded NdFeB magnets, the fillers’ adhesion in the polymer matrix of composites is often insufficient, necessitating filler wettability modification before mixing with liquid polymers. Inductively coupled radiofrequency oxygen plasma was used to modify the surface wettability of commercial NdFeB flakes. A pronounced minimum in water contact angle (WCA) was observed after approximately 100 ms of treatment in plasma (50 Pa, 500 W). A deeper minimum was observed upon treatment in the flowing afterglow. The flux of oxygen atoms on the NdFeB flakes’ surface was ∼3 × 1023 m−2 s−1, and the WCA below 20° was observed after treating the samples in the afterglow for 0.05–0.5 s; corresponding O-atom doses 1022–1023 m−2. Larger doses caused a gradual loss of hydrophilicity, and an initial WCA of ∼75° was established after treating the samples in the afterglow for ∼40 s. This was attributed to the segregation and oxidation of iron on the NdFeB surface. Thorough XPS depth profiling revealed oxidation kinetics. The treatment in the glowing plasma caused a similar evolution, except that hydrophobicity was re-established after 1-s plasma treatment. The segregation of iron on the surface caused the formation of Fe2O3, and the intermediate layer toward the bulk consisted of Nd2O3 dispersed in the Fe matrix.

Druh

J_SC - Článek v periodiku v databázi SCOPUS

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Applied Surface Science

ISSN

0169-4332

e-ISSN

—

Svazek periodika

713

Číslo periodika v rámci svazku

Neuveden

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

12

Strana od-do

nestránkováno

Kód UT WoS článku

001694847100001

EID výsledku v databázi Scopus

2-s2.0-105013657020