Ab initio investigation of osmium carbide

Stability field of the high-(P, T) Re2C phase and properties of an analogous osmium carbide phase

“…These studies are, however, limited to osmium carbides with a 1:1 composition, and in parts contradict each other. For example, osmium carbide with the WC-structure type is sometimes computed to be 'mechanically and electronically' unstable [6,7,9], while in other studies this polymorph is found to be the most stable [8,10]. The simulated X-ray powder patterns of OsC in either the WC-or NiAs-structure type bear no resemblance at all to the experimentally determined pattern [7].…”

“…In contrast to this, there are numerous theoretical studies aimed at studying superhard or ultrastiff osmium carbides e.g. [6][7][8][9][10]. These studies are, however, limited to osmium carbides with a 1:1 composition, and in parts contradict each other.…”

Structural stability and phase transition in OsC and RuC

“…Four reports appeared in 2008. [9][10][11][12] The GGA study by Zemzemi and Hebbache 9 indicated that OsC in WC structure is mechanically unstable due to the small C 44 value. By using the projector-augmented wave (PAW) method and local density approximation (LDA), Wang 10 studied the OsC in WC, FeSi, and OsSi (CsCl) structures.…”

First-principles investigation of technetium carbides and nitrides

“…8 Although Kempter and Nadler 12 claimed to have synthesized WC-structured OsC at ambient pressure and high temperature many years ago, its crystal structure has been disputed and no prominent hardness has yet been found in several phases. [13][14][15][16] Fortunately, OsN 2 has been successfully synthesized, but the exact structures is still not well resolved. 19 In order to hunt for new hard materials, researchers start to look closely at other transition-metal elements surrounding Os in the periodic table.…”