{\omega} structure in steel: a first-principles study

TL;DR

This study uses first-principles calculations to investigate the stability of the {} structure in steel, focusing on the effects of interstitial carbon atoms and concluding it is generally unstable except under specific atomic constraints.

Contribution

It provides a detailed first-principles analysis of the {} structure's stability in steel, highlighting the impact of interstitial C atoms and conditions for formation.

Findings

Interstitial C atoms increase the energy of the {} structure.

The {} structure is mechanically unstable unless C concentration reaches 25 at%.

The {} structure may form under special atomic constraints at interfaces.

Abstract

Recent experimental works reported observation of the {\omega} structure in steel. Here, stability of the {\omega} structure in steel is investigated based on first-principles with special interests in effects of interstitial C atoms. The interstitial C atoms increase the energy of the {\omega} structure compared with the ferromagnetic (FM) BCC. The {\omega} structure incorporating C atoms is also mechanically unstable unless the C concentration is 25 at.%. It is concluded that the {\omega} structure is mostly unstable in steel, and the {\omega} structure in steel may be formed under special atomic constraints at twin boundaries or other interfaces.