Simon Clark

Osmium Diboride, An Ultra-Incompressible, Hard Material

Journal of The American Chemical Society, 2005

Ultra-incompressible, hard materials are of great interest due to their usefulness in a wide vari... more Ultra-incompressible, hard materials are of great interest due to their usefulness in a wide variety of industrial applications. These include abrasives, cutting tools, and coatings where wear prevention, scratch resistance, surface durability, and chemical stability are a priority. 1,2 Therefore, the development of a new class of hard materials is of great practical interest. In this paper, we demonstrate that valence electron density and bond covalency can be used as design parameters for creating ultra-incompressible, hard materials. As an example, we report on the synthesis, bulk modulus, and preliminary hardness testing of osmium diboride, OsB 2 .

$Figure 2. Comparison of the compressibility of the individual lattice param- eters of OsB2 with diamond. The a (blue), b (pink), and c (green) parameters in OsB2 are fit with straight lines, while the diamond line (black) is taken from ref 4. Note that the c-axis in OsB is less compressible than diamond. Figure 1. Pressure versus fractional unit cell volume for OsB2 (lM, a, and —), corundum (- - -), and diamond (- « -).!9 Both the literature curves and OsB2 fit correspond to the third-order Birch-Murnaghan equation of state: P = (°/2)Bol(VVo)-78 — (Vo) >} {1 — C/a)(4 — Bo’ )I(V/Vo)-23 — 1]}.$

Download

Uploads

Papers by Simon Clark

Log In