International Journal of Physics

International Journal of Physics | Vol. 6, No. 2, February 2015 | pp. 9–16

DOI: 10.46882/2015/IJP/000058

Research Article

Title: Elasticity Profiles and High-Pressure Phase Transitions in Ultra-Incompressible Rhenium Diboride

Names of Authors: V. I. Morozov¹, E. M. Gallagher²

Authors’ Affiliations: ¹Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia; ²School of Physics, Trinity College Dublin, Dublin, Ireland

Abstract: Developing ultra-incompressible structural materials capable of operating under extreme mechanical stress is vital for specialized industrial machining and deep-earth simulation components. This paper investigates the high-pressure elastic profiles and monitors structural phase transitions in hexagonal rhenium diboride (ReB²) up to hydrostatic pressures of 150.0 GPa. We performed first-principles density functional theory computations within the generalized gradient approximation framework. At zero pressure, the calculated bulk modulus is B0 = 344.0 GPa, with an elastic pressure derivative value of B0' = 4.08, matching experimental diamond anvil cell measurements within a 1.2% margin. The single-crystal elastic constants (C11, C33, C44, C12, and C13) increase monotonically under uniform compression, satisfying all Born mechanical stability parameters across the entire pressure range. The directional compressibility paths reveal that the crystal c-axis displays exceptional stiffness due to short, covalent rhenium-boron bonds. Electronic structure computations show a high density of states at the Fermi level, indicating that ReB² maintains its metallic profile under ultra-high pressures. These precise elastic records confirm the viability of transition metal borides as robust alternatives to conventional superhard diamond materials.

Keywords: Rhenium diboride; density functional theory; elastic constants; high pressure; structural stability; mechanical properties

Manuscript Timeline: Received: November 11, 2014; Revised: December 19, 2014; Accepted: January 08, 2015; Published: February 12, 2015

Citation: Morozov, V. I., & Gallagher, E. M. (2015). Elasticity Profiles and High-Pressure Phase Transitions in Ultra-Incompressible Rhenium Diboride. International Journal of Physics, 6(2), 9–16.