Abstract
Nanocrystalline tungsten oxide (WO3) thin films synthesized by thermal oxidation of tungsten substrates were exposed to low energy helium ions (energy: 80 eV; flux: 1.4-1.7 ×1020 m-2 s-1) at room temperature and at 673 K. The structure and morphology changes of the oxide were studied using Raman spectroscopy and electron microscopy. Due to the low ion energy, no erosion is observed at room temperature. In contrast, at 673 K, a color change is observed and a significant erosion is measured (∼70 nm for a fluence of ∼4 ×1021 m-2) due to a synergetic effect between ion bombardment and heating. We show that erosion processes and structural changes strongly depend on the ion fluence and in particular the higher the fluence, the lower the erosion yield, most likely due to oxygen depletion in the oxide near-surface layers.
| Original language | English |
|---|---|
| Article number | 014019 |
| Journal | Physica Scripta |
| Volume | 2017 |
| Issue number | T170 |
| DOIs | |
| State | Published - Dec 1 2017 |
| Event | 16th International Conference on Plasma-Facing Materials and Components for Fusion Applications, PFMC 2017 - Neuss/Dusseldorf, Germany Duration: May 16 2017 → May 19 2017 |
Funding
This work was carried out within the framework of EURO-fusion Consortium and received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. It was also supported by the A*MIDEX project (no ANR-11-IDEX-0001-02) sponsored by the ‘Investisse-ments d’Avenir’ French Government programme, managed by the French National Research Agency (ANR).