Superhard Hexagonal sp3-Bonded BN Polytypes and BC2N from Crystal Chemistry and First Principles

IF 1.2 4区材料科学 Q4 MATERIALS SCIENCE, MULTIDISCIPLINARY

Journal of Superhard Materials Pub Date : 2024-06-17 DOI:10.3103/S1063457624020060

Samir F. Matar, Vladimir L. Solozhenko

引用次数: 0

Abstract

In the framework of a crystallochemical approach, new hexagonal (P6₃/mc) sp³-bonded BN polytypes (4H, 6H and 8H) and ternary BC₂N were proposed by rationalized substitutions of C for B and N in hexagonal carbon allotrope C₈ (4C carbon) with cfc topology, and density functional theory calculations of their ground states were performed. All new phases were found to be cohesive and stable mechanically (elastic constants) and dynamically (phonon band structures). According to modern models of hardness, the new phases were recognized as superhard with Vickers hardness above 50 GPa. Their electronic band structures exhibit insulating behavior with large band gaps.

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从晶体化学和第一性原理看超硬六方 sp3 键 BN 聚类和 BC2N

摘要在晶体化学方法的框架内，通过在具有 cfc 拓扑结构的六方碳素同素异形体 C8（4C 碳素）中用 C 合理取代 B 和 N，提出了新的六方（P63/mc）sp3 键 BN 多型（4H、6H 和 8H）和三元 BC2N，并对它们的基态进行了密度泛函理论计算。研究发现，所有新相都具有内聚性，并且在机械（弹性常数）和动力学（声子带结构）方面都很稳定。根据现代硬度模型，这些新相被认定为维氏硬度超过 50 GPa 的超硬物相。它们的电子能带结构表现出绝缘特性，具有较大的能带间隙。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Superhard Materials MATERIALS SCIENCE, MULTIDISCIPLINARY-

CiteScore

1.80

自引率

66.70%

发文量

审稿时长

2 months

期刊介绍： Journal of Superhard Materials presents up-to-date results of basic and applied research on production, properties, and applications of superhard materials and related tools. It publishes the results of fundamental research on physicochemical processes of forming and growth of single-crystal, polycrystalline, and dispersed materials, diamond and diamond-like films; developments of methods for spontaneous and controlled synthesis of superhard materials and methods for static, explosive and epitaxial synthesis. The focus of the journal is large single crystals of synthetic diamonds; elite grinding powders and micron powders of synthetic diamonds and cubic boron nitride; polycrystalline and composite superhard materials based on diamond and cubic boron nitride; diamond and carbide tools for highly efficient metal-working, boring, stone-working, coal mining and geological exploration; articles of ceramic; polishing pastes for high-precision optics; precision lathes for diamond turning; technologies of precise machining of metals, glass, and ceramics. The journal covers all fundamental and technological aspects of synthesis, characterization, properties, devices and applications of these materials. The journal welcomes manuscripts from all countries in the English language.