From layered 2D carbon to 3D tetrahedral allotropes C12 and C18 with physical properties related to diamond: Crystal chemistry and DFT investigations

IF 9.1 2区化学 Q1 CHEMISTRY, INORGANIC & NUCLEAR

Progress in Solid State Chemistry Pub Date : 2024-10-16 DOI:10.1016/j.progsolidstchem.2024.100492

Samir F. Matar

{"title":"From layered 2D carbon to 3D tetrahedral allotropes C12 and C18 with physical properties related to diamond: Crystal chemistry and DFT investigations","authors":"Samir F. Matar","doi":"10.1016/j.progsolidstchem.2024.100492","DOIUrl":null,"url":null,"abstract":"<div><div>Mechanisms of changes from 2D to 3D (D = dimensionality) involving 2D C(sp2) trigonal paving to C(sp3) tetrahedral stacking are proposed through puckering of the 2D layers on one hand and interlayer insertion of extra C on the other hand. Such transformations, led to 3D hexagonal C12 and C18 allotropes respectively characterized by lon and bac topologies. Using density functional theory DFT calculations, the two allotropes were found cohesive and stable both mechanically (elastic properties) and dynamically (phonons). Comparisons of the physical properties with known uni C6 were established letting identify ranges of large Vickers hardness: HV (uni C6) = 89 GPa, HV (lon C12) = 97 GPa, and HV (bac C18) = 70 GPa. Whilst C6 was identified with acoustic phonons instability, C12 and C18 were found stable dynamically throughout the acoustic and optic frequency ranges. Furthering on the thermal properties the allotropes were characterized with a temperature dependence curve of the specific heat CV close to experimental data of diamond with best fit for novel C18. The electronic band structures reveal a small band gap of 1 eV for uni C6 and larger direct band gap of 3 eV for the two other 3D allotropes. Such modulations of the electronic and physical properties should open scopes of carbon research.</div></div>","PeriodicalId":415,"journal":{"name":"Progress in Solid State Chemistry","volume":"76 ","pages":"Article 100492"},"PeriodicalIF":9.1000,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Progress in Solid State Chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0079678624000554","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}

引用次数: 0

Abstract

Mechanisms of changes from 2D to 3D (D = dimensionality) involving 2D C(sp²) trigonal paving to C(sp³) tetrahedral stacking are proposed through puckering of the 2D layers on one hand and interlayer insertion of extra C on the other hand. Such transformations, led to 3D hexagonal C₁₂ and C₁₈ allotropes respectively characterized by lon and bac topologies. Using density functional theory DFT calculations, the two allotropes were found cohesive and stable both mechanically (elastic properties) and dynamically (phonons). Comparisons of the physical properties with known uni C₆ were established letting identify ranges of large Vickers hardness: H_V (uni C₆) = 89 GPa, H_V (lon C₁₂) = 97 GPa, and H_V (bac C₁₈) = 70 GPa. Whilst C₆ was identified with acoustic phonons instability, C₁₂ and C₁₈ were found stable dynamically throughout the acoustic and optic frequency ranges. Furthering on the thermal properties the allotropes were characterized with a temperature dependence curve of the specific heat C_V close to experimental data of diamond with best fit for novel C₁₈. The electronic band structures reveal a small band gap of 1 eV for uni C₆ and larger direct band gap of 3 eV for the two other 3D allotropes. Such modulations of the electronic and physical properties should open scopes of carbon research.

查看原文本刊更多论文

从层状二维碳到具有与金刚石相关物理性质的三维四面体同素异形体 C12 和 C18：晶体化学和 DFT 研究

提出了从二维到三维（D = 维度）的变化机制，其中涉及二维 C（sp2）三维铺层到 C（sp3）四面体堆叠，一方面是通过二维层的起皱，另一方面是通过层间插入额外的 C。这种转变导致了分别以 lon 和 bac 拓扑为特征的三维六边形 C12 和 C18 同素异形体。通过密度泛函理论 DFT 计算，发现这两种同素异形体在机械（弹性特性）和动力学（声子）方面都具有内聚性和稳定性。将其物理性质与已知的 uni C6 进行比较，确定了大维氏硬度的范围：HV（uni C6）= 89 GPa，HV（lon C12）= 97 GPa，HV（bac C18）= 70 GPa。C6 具有声子不稳定性，而 C12 和 C18 则在整个声学和光学频率范围内具有动态稳定性。此外，在热特性方面，同素异形体的比热 CV 随温度变化的曲线与金刚石的实验数据接近，新型 C18 的曲线拟合度最高。电子能带结构显示，单晶 C6 的能带间隙较小，为 1 eV，而其他两种三维同素异形体的直接能带间隙较大，为 3 eV。这种电子和物理性质的变化将为碳研究开辟新的领域。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Progress in Solid State Chemistry 化学-无机化学与核化学

CiteScore

14.10

自引率

3.30%

发文量

期刊介绍： Progress in Solid State Chemistry offers critical reviews and specialized articles written by leading experts in the field, providing a comprehensive view of solid-state chemistry. It addresses the challenge of dispersed literature by offering up-to-date assessments of research progress and recent developments. Emphasis is placed on the relationship between physical properties and structural chemistry, particularly imperfections like vacancies and dislocations. The reviews published in Progress in Solid State Chemistry emphasize critical evaluation of the field, along with indications of current problems and future directions. Papers are not intended to be bibliographic in nature but rather to inform a broad range of readers in an inherently multidisciplinary field by providing expert treatises oriented both towards specialists in different areas of the solid state and towards nonspecialists. The authorship is international, and the subject matter will be of interest to chemists, materials scientists, physicists, metallurgists, crystallographers, ceramists, and engineers interested in the solid state.