Theoretical study on the controllable preparation of superhard BC₂N under high pressure

Abstract

High-density B-C-N ternary compounds have attracted considerable attention due to their potential and excellent properties combined with diamond and cubic boron nitride (c-BN). However, the development of B-C-N is restricted...

Moiré-of-Moiré phases formed in twisted graphene/hexagonal boron nitride heterostructures under high pressure

“…18 Gao et al constructed two distinct graphene/h-BN superlattices and employed diverse compression methods to generate five different ternary B–N–C structures, thus revealing a controllable phase transition mechanism. 26 These studies collectively highlight the potential of layered graphene/h-BN heterostructures as ideal precursors for synthesizing superhard ternary B–N–C compounds. Meanwhile, theoretical predictions play a crucial role in offering invaluable atomic-scale insights, which in turn bolster advancements in experimental research methodologies.…”

“…1b). 44 To alleviate the 1.8% lattice mismatch between graphene and h-BN, slight strain is applied to the h-BN layer, 26,41 the common supercell is then obtained by rotating the cell with basis vector t 1 (na 1 + ma 2 ) by y/2, and the cell with basis vector t 2 ((n + m)a 1 À ma 2 ) by Ày/2 (Fig. 1b).…”

“…Recently, two-dimensional (2D) materials, such as graphene and hexagonal boron–nitride (h-BN), have emerged as promising precursors facilitating precise engineering of nanoscale stacking arrangements. 23,24 This engineered manipulation has led to the creation of diverse B–N–C phases through interlayer compression, 25,26 akin to the transformation from graphite to diamond. 27 Heterostructures of graphene and h-BN have been successfully prepared in experiments.…”

“…This structure exhibits superior hardness compared to cBN, such as 79.4 GPa for (3,0)-BC 2 N 21 and 72 GPa for 3D (6,6)-BC 2 N. 22 This discovery emphasizes the critical role of precursor selection as a fundamental pathway for exploring ternary B-N-C phases.Recently, two-dimensional (2D) materials, such as graphene and hexagonal boron-nitride (h-BN), have emerged as promising precursors facilitating precise engineering of nanoscale stacking arrangements. 23,24 This engineered manipulation has led to the creation of diverse B-N-C phases through interlayer compression, 25,26 akin to the transformation from…”

Novel superhard semiconducting structures of C8B2N2 predicted using the first-principles approach

“…Solozhenko et al 8 successfully synthesized c-BC 2 N, which exhibits a hardness only slightly lower than that of diamond, under conditions exceeding 2200 K and 18 GPa. Subsequently, a plethora of BC 2 N structures were postulated, including R3m-BC 2 N, t-BC 2 N and dia-BC 2 N. [9][10][11][12][13] The electronic structures and mechanical properties of six possible B 2 C 2 N 2 structures derived from 3C-SiC unit cells were scrutinized. The findings reveal that B 2 C 2 N 2 -1 serves as a wide-gap semiconductor with hardness surpassing that of c-BN.…”