Carbon-induced ionocovalence in MgH2 storage material

Samir F. Matar

Carbon-induced ionocovalence in MgH2 storage material

Materials Science 2012-12-14 v2

Authors: Samir F. Matar

Abstract

The overall large ionic character of MgH2 is reduced by inserting light elements from the first period, B and C, using a trirutile host superstructure. Both elements are found destabilizing to the structure with largely positive cohesive energy with interstitial B and slightly negative cohesive energy with interstitial C. This trend is also observed for low amounts of insertion down to (B,C)0.167MgH2. From the Bader charge analysis the largely ionic character of hydrogen is decreased to an average H-0.37 in the neighborhood of C and H-0.75 for the other hydrogen atoms atoms (resp. H-0.64 and H-0.76 for B insertion). This peculiar behavior should enable enhancing the kinetics of H release for potential applications.

Keywords

MgH2 hydrogen storage carbon insertion ionic-covalent character cohesive energy Bader charge analysis trirutile superstructure

Cite

@article{arxiv.1212.0697,
  title  = {Carbon-induced ionocovalence in MgH2 storage material},
  author = {Samir F. Matar},
  journal= {arXiv preprint arXiv:1212.0697},
  year   = {2012}
}

Comments

Withdrawn because a more complete version (C & B) has been accepted for publication with Computational Materials Science (Elsevier) on 12/12/12!

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