A first-principles study on three-dimensional covalently-bonded hexagonal boron nitride nanoribbons

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Boron nitride (BN) exists in various allotropes with diverse properties.
• Nanostructured BN materials offer unique characteristics for advanced applications.
• Understanding the structure-property relationships of novel BN allotropes is crucial.

Purpose of the Study:

• To investigate the structural, mechanical, and electronic properties of three-dimensional honeycomb-structure boron nitride nanoribbons (CBBNs).
• To compare the properties of CBBNs with other carbon and BN allotropes.
• To explore the potential of CBBNs as stable and hard materials.

Main Methods:

• Utilized first-principles calculations and the tight-binding method.
• Studied CBBNs of various sizes, focusing on sp(3)-bonded hexagonal BN nanoribbons.
• Analyzed structural, mechanical, thermal stability, and electronic band structures.

Main Results:

• CBBNs exhibit high porosity and low mass density but possess mechanical hardness comparable to cubic BN.
• CBBNs behave as a binary alloy of sp(2)- and sp(3)-bonded BNs, following Vegard's rule for average bond lengths and bulk moduli.
• The band gap of CBBNs varies with size, influenced by interactions between sp(2)-bonded atoms in adjacent nanoribbons.

Conclusions:

• Despite high porosity, CBBNs are mechanically robust and thermally stable materials.
• CBBNs demonstrate tunable electronic properties, suggesting potential for electronic applications.
• The study provides insights into the fundamental properties of a novel BN allotrope.