Elastic moduli and hardness of highly incompressible platinum perpnictide PtAs2

Abstract

PtAs2 appears to be the least compressible known arsenide with a bulk modulus of 220(5) GPa and a shear modulus of between 64 and 77 GPa. PtAs2 has a hardness of 11(1) GPa, which is remarkably high for an arsenide. These elastic and mechanical properties in combination with the known chemical inertness and the small indirect band gap add interest to the use and occurrence of PtAs2 at Pt-GaAs contacts in transistors. We note the modest fracture toughness of 1.1–1.6 MPa m1/2 of PtAs2.

Monoclinic C2/m-20 carbon: a novel superhard sp3carbon allotrope

“…The most extraordinary thing is that the band gap increases with the increasing pressure. This trend has been explained by Oliver Tschauner et al 62 using the Bader charge analysis and other articles. 42,63,64…”

High Pressure and High Temperature Synthesis of the Iron Pernitride FeN2

“…Additionally, this further underlines the plausibility of a bond order of 1.5 (over one of greater value) as it suggests a significant filling of the antibonding orbitals. Of course, as demonstrated in PtAs 2 , other parameters such as the structure and charge transfer behavior with pressure can also have an effect, although here deemed minor, on a solid’s compressibility …”

“…Of course, as demonstrated in PtAs 2 , other parameters such as the structure and charge transfer behavior with pressure can also have an effect, although here deemed minor, on a solid's compressibility. 53 Upon reaching ambient pressure during the sample decompression, new low intensity X-ray diffraction lines were detected, adding to those belonging to marcasite FeN 2 and NiAs-FeN. These diffraction lines were unambiguously determined to match a hexagonal (R3̅ m) structure with a = 2.855(1) Å and c = 10.605(1) Å, as shown through a Le Bail refinement (Figure 5).…”

Pressure-Dependent Crystal Radii

“…This conclusion is also consistent with experimental observation. Although it is not possible to extract good cation-oxide distances from X-ray diffraction data from high-pressure experiments on compounds of elements with such high form factors, it is known that compounds of L = 5 and 6 group VIIIb elements are quite incompressible which, in part, is explained by low cationic compressibility for simple compounds of these elements [81][82][83].…”