Crystal structures, bonding and electronic structures of α- and β-Ir₂B_3- compounds.

Area of Science:

• Materials Science
• Solid State Chemistry
• Crystallography

Background:

• Binary boron-rich compounds are crucial for advanced material applications.
• Iridium borides have garnered interest due to their unique structural and electronic properties.
• Previous studies on iridium borides require further structural and electronic characterization.

Purpose of the Study:

• To synthesize and characterize novel iridium boride phases, specifically α-Ir₂B_3- and β-Ir₂B_3-.
• To elucidate the crystal structures of these new compounds using X-ray diffraction.
• To investigate the electronic properties and bonding characteristics using Density Functional Theory (DFT) calculations.

Main Methods:

• Synthesis via arc melting and high-temperature thermal treatment.
• Single crystal and powder X-ray diffraction for structural determination.
• Density Functional Theory (DFT) calculations for electronic structure analysis.

Main Results:

• Successful synthesis of α-Ir₂B_3- (space group C2/m) and β-Ir₂B_3- (space group Pnma).
• Detailed structural analysis revealed distinct arrangements of iridium and boron atoms, including boron hexagons and ribbons.
• DFT calculations predicted metallic behavior for both compounds, with differing electronic densities of states (eDOS) at the Fermi level and identified covalent and metallic bonding interactions.

Conclusions:

• The study successfully synthesized and structurally characterized two new iridium boride phases, α-Ir₂B_3- and β-Ir₂B_3-.
• The distinct crystal structures and electronic properties, including metallic behavior, were confirmed through experimental and computational methods.
• The findings provide insights into the structure-property relationships of iridium borides and their potential for future applications.