Cubic to hexagonal iron phase transition promoted by interstitial hydrogen

2011/06/02 by Alejandro Castedo, A. Castedo, J. Sanchez +11
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Hydrogen Storage and Materials #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci

paper · pdf · doi:10.48550/arxiv.1106.0386

arxiv created 2011/06/02 · openalex publication_date 2011/06/02 · arxiv updated 2011/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

Using ab-initio density functional theory we study the role of interstitial hydrogen on the energetics of the phase transformation of iron from bcc to hcp along Bain's pathway. The impurity creates an internal stress field that can be released through a tetragonal distortion of the lattice, promoting the bcc (ferromagnetic) → fcc (frustrated antiferromagnetic) → hcp (ferromagnetic) transition. The transformation between crystal systems is accompanied by a drastic magnetic reorganization and sudden variations of the unit cell volume, that can be one of the reasons for embrittlement and mechanical failure of iron upon hydrogen adsorption.

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