International Journal of Physics | Vol. 8, No. 1, January 2017 | pp. 1–8
DOI: 10.46882/2017/IJP/000081
Research Article
Title: Elasticity Profiles and High-Pressure Structural Transitions in Ultra-Incompressible Molybdenum Diboride
Names of Authors: V. I. Morozov¹, O. B. Ivanov²
Authors’ Affiliations: ¹Institute of High Pressure Physics, Russian Academy of Sciences, Troitsk, Russia; ²L.D. Landau Institute for Theoretical Physics, Russian Academy of Sciences, Chernogolovka, Russia
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 molybdenum diboride (MoB²) 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 = 315.0 GPa, with an elastic pressure derivative value of B0' = 4.10, 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 molybdenum-boron bonds. Electronic structure computations show a high density of states at the Fermi level, indicating that MoB² 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: Molybdenum diboride; density functional theory; elastic constants; high pressure; structural stability; mechanical properties
Manuscript Timeline: Received: October 12, 2016; Revised: November 27, 2016; Accepted: December 15, 2016; Published: January 16, 2017
Citation: Morozov, V. I., & Ivanov, O. B. (2017). Elasticity Profiles and High-Pressure Structural Transitions in Ultra-Incompressible Molybdenum Diboride. International Journal of Physics, 8(1), 1–8.
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