Revealing an unusual transparent phase of superhard iron tetraboride under high pressure

• First principles-based electronic structure calculations of super-hard iron tetraboride (FeB4) under high pressure have been undertaken in this study. Starting with a "conventional" superconducting phase of this material under high pressure leads to an unexpected phase transition toward a semiconducting one. This transition occurred at 53.7 GPa, and this pressure acts as a demarcation between two distinct crystal symmetries, metallic orthorhombic and semiconducting tetragonal phases, with Pnnm and I4(1)/acd space groups, respectively. In this work, the electron-phonon coupling-derived superconducting T-c has been determined up to 60 GPa and along with optical band gap variation with increasing pressure up to 300 GPa. The dynamic stability has been confirmed by phonon dispersion calculations throughout this study.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

metal-semiconductor phase transition

superhard material

first principle study

high pressure

superconductivity

Publication and Content Type

ref (subject category)

art (subject category)