Z-BN: a novel superhard boron nitride phase

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Hexagonal boron nitride (h-BN) and cubic boron nitride (c-BN) are well-known materials with distinct properties.
• The search for novel boron nitride phases with enhanced properties remains an active area of research.
• Understanding intermediate phases between h-BN and c-BN can lead to new material discoveries.

Purpose of the Study:

• To propose and investigate a new superhard boron nitride phase, Z-BN.
• To determine the structural stability, electronic properties, and mechanical hardness of Z-BN.
• To assess the feasibility of experimental synthesis of Z-BN.

Main Methods:

• First-principles calculations based on density functional theory (DFT).
• Energetic, structural, and electronic property analyses.
• Vickers hardness and transition pressure calculations.

Main Results:

• Z-BN is identified as a stable phase energetically favorable over bct-BN.
• Z-BN exhibits high structural stability and density comparable to c-BN.
• Z-BN is a transparent insulator with an indirect band gap of 5.27 eV and a Vickers hardness of 55.88 GPa.
• Low transition pressure (3.3 GPa) suggests experimental feasibility via cold compression of AB stacking h-BN.

Conclusions:

• Z-BN represents a promising new superhard boron nitride phase.
• Its properties are comparable to those of c-BN, making it a potential candidate for advanced applications.
• The proposed synthesis route offers a viable pathway for experimental realization.