HT‐NbOsB: Experimental and Theoretical Investigations of a Boride Structure Type Containing Boron Chains and Isolated Boron Atoms. Issue 28 (19th June 2018)

• Record Type: Journal Article
• Authors: Forsythe, Ryland; Scheifers, Jan P.; Zhang, Yuemei; Fokwa, Boniface P. T.
• Is Part Of: European journal of inorganic chemistry. Issue 28(2018)
• Page Start: 3297
• Page End: 3303
• Publication Date: 2018-06-19
• Subjects: Niobium Osmium boride -- Crystal structure -- Boron chains -- COHP bonding -- DFT calculations; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201800235
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : The new ternary compound Nb1– x Os1+ x B ( x = 0.17) was synthesized by arc‐melting of the elements in a water‐cooled crucible under an argon atmosphere and was characterized by powder and single‐crystal X‐ray diffraction as well as energy‐dispersive X‐ray spectroscopy (EDX). The compound crystallizes with a new orthorhombic structure type in the space group Pnma (no. 62) with the lattice parameters a = 11.283(2) Å, b = 3.0101(4) Å, and c = 12.883(2) Å. The structure contains isolated boron atoms in osmium trigonal prisms, and boron chains in face‐sharing niobium trigonal prisms. Electronic structure relaxation has confirmed the crystallographic parameters, and crystal orbital Hamilton population (COHP) bonding analysis was used to understand the chemical bonding. It is shown that a local stabilizing effect from replacing Nb with Os is favored despite a global destabilization. Abstract : The new metal boride Nb1– x Os1+ x B, a high‐temperature modification of superconducting NbOsB, crystallizes in a new structure type. This structure contains both isolated boron atoms in trigonal prisms and infinite boron chains in face sharing trigonal prisms. Electronic structure and bonding analyses suggest substituting Nb with Os increases local stability despite a small global destabilization.