Amorphous boron carbide from ab initio simulations

Yildiz T. A., DURANDURDU M.

COMPUTATIONAL MATERIALS SCIENCE, cilt.173, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 173
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.commatsci.2019.109397
  • Dergi Adı: COMPUTATIONAL MATERIALS SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Applied Science & Technology Source, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, INSPEC, Metadex, Civil Engineering Abstracts
  • Abdullah Gül Üniversitesi Adresli: Evet

Özet

An amorphous boron carbide (a-B4C) model is generated by means of ab-initio molecular dynamics calculations within a generalized gradient approximation and its structural, mechanical and electrical features are discussed in details. The mean coordination number of B and C atoms is estimated to be 5.29 and 4.17, respectively. The pentagonal pyramid-like motifs for B atoms, having sixfold coordination, are the main building units in a-B4C and some of which involve with the development of B-12 icosahedra. On the other hand, the fourfold-coordinated units are the leading configurations for C atoms. Surprisingly the formation of C-C bonds is found to be less favorable in the noncrystalline network, compared to the crystal. a-B4C is a semiconducting material having an energy band gap considerably less than that of the crystal. A noticeably decrease in the mechanical properties of B4C is observed by amorphization. Nonetheless a-B4C is categorized as a hard material due to its high Vickers hardness of about 24 GPa.