Materials Properties of Ultra-Incompressible Re₂P

Abstract

ABSTRACT:In situ high-pressure X-ray powder diffraction measurements on Re 2 P up to 37.0 GPa at ambient temperature in diamond-anvil cells were carried out at two different synchrotron facilities (ESRF and DESY). The compressibility of Re 2 P (Pnma, no. 62, a = 5.5464(17), b = 2.9421(8), c = 10.0483(35) Å, V = 163.97(9) Å 3 , Z = 4, R p = 0.1008, wR p = 0.1341 at ambient conditions) was investigated and resulted in a bulk modulus of B 0 = 320(10) GPa after fitting the experimental p-V data to a second-and third-order Birch-Murnaghan equation of state. In addition, the determined bulk modulus is compared to values obtained from an Eulerian strain versus normalized stress plot with values ranging form 315(7) to 321(15) GPa. These experimental findings are confirmed by DFT-calculations ranking Re 2 P amongst ultra-incompressible materials. However, the Vickers hardness of a highpressure sintered Re 2 P-Re x C y composite material in the asymptotic hardness region was found to be of only 13(2) GPa. Electrical conductivity measurements indicate that metallic Re 2 P exhibits Pauli-paramagnetism. Analysis of temperature-dependent in situ Xray diffractometry reveals an approximately isotropic expansion of the lattice parameters with a thermal expansion coefficient of (α(V) = 28.5-32.8(2)·10 -6 K -1 ).

Nanoscaled Metal Borides and Phosphides: Recent Developments and Perspectives

“…260 Other nuclei than 11 B can be used. 278 For instance, superconductivity in MgB 2 was probed by 25 Mg NMR, 279,280 local environment for vanadium in vanadium borides was studied by the Knight shifts in 51 V NMR spectra, 259,281 and site occupancies of sodium in Na 2 B 29 were obtained by combining different sequences in 23 Na solid state NMR (Figure 17). 216 Coupling of 11 B (Figure 17), 29 Si, and 89 Y solid state NMR was also performed.…”

“…In contrast, metal phosphides and metal borides remain mostly exotic for chemists, despite a specific set of properties that already supplied the worldwide industrial market with phosphide semiconductors , and catalysts, but also with bulk boride refractory conductive ceramics, hard magnets, superconductors, and hard materials . Fundamental property aspects of bulk metal borides and metal phosphides are also the focus of many researchers: conduction, , luminescence, field emission, thermoelectric and magnetic properties, ultrahardness, , and behaviors as diffusion barriers are among the current hot topics. Like for many other materials before, novel properties or performance improvements have emerged from nanoscaling.…”

Structure, Relative Stabilities, Physical Properties, and Hardness of Osmium Carbides with Various Stoichiometries: First-Principle Investigations

“…We here apply this idea to osmium carbides to investigate potential structures. Four possible structures were adopted for Os 2 C: both experimental hexagonal Re 2 N ( P 6 3 / mmc ) and orthorhombic Re 2 P ( Pnna ) together with two orthorhombic Ru 2 Si ( Pnma ) and Rh 2 Si ( Pnma ) . For OsC 2 , besides the experimental synthesized OsN 2 ( Pnnm ) and OsB 2 ( Pmmn ), the orthorhombic OsSi 2 ( Cmca ), RhN 2 ( Pnnm ) and FeSi 2 ( Cmca ), tetragonal LaC 2 ( I 4/ mmm ), RuSi 2 ( P 4/ mmm ) and RhSn 2 ( I 4/ mcm ), monoclinic OsGe 2 ( C 12/ m 1), as well as two types of FeS 2 (marcasite: Pnnm ; pyrite: Pa 3̅) , structures were also considered.…”

Elastic, magnetic and electronic properties of iridium phosphide Ir2P

“…However, transition-metal phosphides have received minimum attention up to date. The bonding scheme in this group can be analogous to that of their boride counterparts 24 25 . While the latter is characterized by sharing metal-metalloid (M-P) bonds with a strong covalent component, transition metal phosphides have strong and highly metalloid-metalloid (P-P) bonds.…”