First-principles study of C6B2

Kazuaki Kobayashi, Yuji Zenitani, Jun Akimitsu

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We calculate the electronic and lattice properties of C6B 2 (Na3As type crystal structure) using the first-principles molecular dynamics (FPMD) method. C6B2 is a hypothetical hexagonal compound, which consists of two B-C layers and two C-C layers. All calculated electronic band structures are metallic. C 6B2 has unoccupied flat bands close to the Fermi level at the Γ-A line. These flat bands correspond to unoccupied σ-bands of MgB2 at the Γ-A line. Displacements of B atoms along a B-C bond split unoccupied flat bands at the Γ-A line into two subbands. A total energy change with displacements of B atoms indicates anharmonicity of a B-C stretching mode. We investigate C6B2 under various compression conditions. The change in the electronic band structure under a, b-axis compression (Pxy) is small. In contrast, it is quite remarkable under c-axis compression (Pz). We find the lattice anomaly of C6B2 under a, b-axis compression. This anomaly shows a kind of negative Poisson ratios.

Original languageEnglish
Pages (from-to)374-380
Number of pages7
JournalPhysica C: Superconductivity and its Applications
Volume426-431
Issue numberI
DOIs
Publication statusPublished - Oct 1 2005
Externally publishedYes

Fingerprint

Band structure
Atoms
Poisson ratio
Fermi level
Crystal lattices
Stretching
Molecular dynamics
Compaction
Crystal structure
electronics
anomalies
atoms
molecular dynamics
crystal structure
energy

Keywords

  • CB
  • Electronic band structure
  • First principles
  • Lattice anomaly

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

First-principles study of C6B2 . / Kobayashi, Kazuaki; Zenitani, Yuji; Akimitsu, Jun.

In: Physica C: Superconductivity and its Applications, Vol. 426-431, No. I, 01.10.2005, p. 374-380.

Research output: Contribution to journalArticle

Kobayashi, Kazuaki ; Zenitani, Yuji ; Akimitsu, Jun. / First-principles study of C6B2 . In: Physica C: Superconductivity and its Applications. 2005 ; Vol. 426-431, No. I. pp. 374-380.
@article{93cca7d18e194073858e4a2e32805bbf,
title = "First-principles study of C6B2",
abstract = "We calculate the electronic and lattice properties of C6B 2 (Na3As type crystal structure) using the first-principles molecular dynamics (FPMD) method. C6B2 is a hypothetical hexagonal compound, which consists of two B-C layers and two C-C layers. All calculated electronic band structures are metallic. C 6B2 has unoccupied flat bands close to the Fermi level at the Γ-A line. These flat bands correspond to unoccupied σ-bands of MgB2 at the Γ-A line. Displacements of B atoms along a B-C bond split unoccupied flat bands at the Γ-A line into two subbands. A total energy change with displacements of B atoms indicates anharmonicity of a B-C stretching mode. We investigate C6B2 under various compression conditions. The change in the electronic band structure under a, b-axis compression (Pxy) is small. In contrast, it is quite remarkable under c-axis compression (Pz). We find the lattice anomaly of C6B2 under a, b-axis compression. This anomaly shows a kind of negative Poisson ratios.",
keywords = "CB, Electronic band structure, First principles, Lattice anomaly",
author = "Kazuaki Kobayashi and Yuji Zenitani and Jun Akimitsu",
year = "2005",
month = "10",
day = "1",
doi = "10.1016/j.physc.2005.01.031",
language = "English",
volume = "426-431",
pages = "374--380",
journal = "Physica C: Superconductivity and its Applications",
issn = "0921-4534",
publisher = "Elsevier",
number = "I",

}

TY - JOUR

T1 - First-principles study of C6B2

AU - Kobayashi, Kazuaki

AU - Zenitani, Yuji

AU - Akimitsu, Jun

PY - 2005/10/1

Y1 - 2005/10/1

N2 - We calculate the electronic and lattice properties of C6B 2 (Na3As type crystal structure) using the first-principles molecular dynamics (FPMD) method. C6B2 is a hypothetical hexagonal compound, which consists of two B-C layers and two C-C layers. All calculated electronic band structures are metallic. C 6B2 has unoccupied flat bands close to the Fermi level at the Γ-A line. These flat bands correspond to unoccupied σ-bands of MgB2 at the Γ-A line. Displacements of B atoms along a B-C bond split unoccupied flat bands at the Γ-A line into two subbands. A total energy change with displacements of B atoms indicates anharmonicity of a B-C stretching mode. We investigate C6B2 under various compression conditions. The change in the electronic band structure under a, b-axis compression (Pxy) is small. In contrast, it is quite remarkable under c-axis compression (Pz). We find the lattice anomaly of C6B2 under a, b-axis compression. This anomaly shows a kind of negative Poisson ratios.

AB - We calculate the electronic and lattice properties of C6B 2 (Na3As type crystal structure) using the first-principles molecular dynamics (FPMD) method. C6B2 is a hypothetical hexagonal compound, which consists of two B-C layers and two C-C layers. All calculated electronic band structures are metallic. C 6B2 has unoccupied flat bands close to the Fermi level at the Γ-A line. These flat bands correspond to unoccupied σ-bands of MgB2 at the Γ-A line. Displacements of B atoms along a B-C bond split unoccupied flat bands at the Γ-A line into two subbands. A total energy change with displacements of B atoms indicates anharmonicity of a B-C stretching mode. We investigate C6B2 under various compression conditions. The change in the electronic band structure under a, b-axis compression (Pxy) is small. In contrast, it is quite remarkable under c-axis compression (Pz). We find the lattice anomaly of C6B2 under a, b-axis compression. This anomaly shows a kind of negative Poisson ratios.

KW - CB

KW - Electronic band structure

KW - First principles

KW - Lattice anomaly

UR - http://www.scopus.com/inward/record.url?scp=25444439526&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=25444439526&partnerID=8YFLogxK

U2 - 10.1016/j.physc.2005.01.031

DO - 10.1016/j.physc.2005.01.031

M3 - Article

AN - SCOPUS:25444439526

VL - 426-431

SP - 374

EP - 380

JO - Physica C: Superconductivity and its Applications

JF - Physica C: Superconductivity and its Applications

SN - 0921-4534

IS - I

ER -