Superhard transition metal tetranitrides: XN4 (X=Re, Os, W)


AYDIN S., ÇİFTCİ Y., Tatar A.

JOURNAL OF MATERIALS RESEARCH, vol.27, no.13, pp.1705-1715, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 27 Issue: 13
  • Publication Date: 2012
  • Doi Number: 10.1557/jmr.2012.131
  • Journal Name: JOURNAL OF MATERIALS RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1705-1715
  • Gazi University Affiliated: Yes

Abstract

The structural, mechanical, and electronic properties of rhenium, osmium, and tungsten tetranitrides, XN4 (X = Re, Os, W) with the orthorhombic ReP4-type structure have been investigated by first-principles calculations using density functional plane-wave pseudopotential method. The calculated formation enthalpies and elastic constants show that these tetranitrides are energetically and mechanically stable. It is appeared from the calculated band structures and density of states that ReN4 and new proposed WN4 are metallic, while OsN4 is semiconductor with a band gap of 0.64 eV. The hardness values of all compounds obtained from different hardness methods indicate that these tetranitrides are superhard materials.