1 Retraction to: Applied Physics A (2021) 127:1–10 https://doi.org/10.1007/s00339-021-04719-y

The Editor-in-Chief has retracted this article. After publication, concerns were raised regarding the presented data. Specifically:

•The data points in Fig. 4 panels a and b appear nearly identical;

•The curves appear highly similar in Fig. 5;

•Repetitive elements are presented in the SEM image in Fig. 8.

The Editor-in-Chief therefore no longer has confidence in the presented data.

Authors Abdallah Ouerdane and Ibrahim Yahiaoui agree to this retraction. Authors Zoubir Hachoun, Aminjon Gulakhmadov and Xi Chen have not responded to any correspondence from the editor or publisher about this retraction.