Possible routes for synthesis of new boron-rich Fe-B and Fe(1-x)Cr(x)B4 compounds

TL;DR

This study uses ab initio calculations to explore the stability and synthesis routes of novel boron-rich Fe-B and Fe(1-x)Cr(x)B4 compounds, highlighting pressure effects and potential for harder materials.

Contribution

It identifies new stable boron-rich phases under pressure and suggests a feasible synthesis pathway for oP10-Fe(x)Cr(1-x)B4 compounds with unique electronic and mechanical properties.

Findings

oP10-FeB4 and oP12-FeB2 are stabilized under pressure

Chromium tetraboride prefers the oP10 structure over oI10

Proposed compounds are expected to be harder than existing Fe-B materials

Abstract

We use ab initio calculations to examine thermodynamic factors that could promote the formation of recently proposed unique oP10-FeB4 and oP12-FeB2 compounds. We demonstrate that these compact boron-rich phases are stabilized further under pressure. We also show that chromium tetraboride is more stable in the new oP10 rather than the reported oI10 structure which opens up the possibility of realizing an oP10-Fe(x)Cr(1-x)B4 pseudobinary material. In addition to exhibiting remarkable electronic features, oP10-FeB4 and oP12-FeB2 are expected to be harder than the known Fe-B compounds commonly used for hard coating applications.