Ab initio study of boron-rich amorphous boron carbides

Yıldız T. A., DURANDURDU M.

Journal of the American Ceramic Society, vol.106, no.5, pp.2862-2874, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 106 Issue: 5
  • Publication Date: 2023
  • Doi Number: 10.1111/jace.18979
  • Journal Name: Journal of the American Ceramic Society
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Periodicals Index Online, Aerospace Database, Applied Science & Technology Source, Art Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, EBSCO Education Source, INSPEC, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.2862-2874
  • Keywords: amorphous, boron carbide, boron-rich, first-principles calculations, mechanical properties
  • Abdullah Gül University Affiliated: Yes

Abstract

Amorphous boron carbide compositions having high B contents (BxC1−x, 0.50 ≤ x ≤ 0.95) are systematically created by way of ab initio molecular dynamics calculations, and their structural, electrical, and mechanical characteristics are inclusively investigated. The coordination number of both B and C atoms increases progressively with increasing B/C ratio and more close-packed materials having pentagonal pyramid motifs form. An amorphous diamond-like local arrangement is found to be dominant up to 65% B content, and beyond this content, a mixed state of amorphous diamond– and B-like structures is perceived in the models because sp3 hybridization around C atoms is still leading one for all compositions. The pentagonal pyramid motifs around C atoms are anticipated to appear beyond 65% content. The intericosahedral linear C–B–C chains do not form in any model. All amorphous boron carbides are semiconducting materials. The mechanical properties gradually increase with increasing B concentration, and some amorphous compositions are proposed to be hard materials on the basis of their Vickers hardness estimation.