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Updated: Jul 16, 2026

Determining the Mechanical Strength of Ultra-Fine-Grained Metals
Published on: November 22, 2021
Ultrastiff cubic TiO2 identified via first-principles calculations
Varghese Swamy1, Barry C Muddle
1Department of Materials Engineering, Monash University, Victoria 3800, Australia. Varghese.Swamy@eng.monash.edu.au
Abstract:
The crystal structures and compressibilities of fluorite- and pyrite-structured TiO2 under varying hydrostatic pressures are calculated using gradient-corrected density functional as well as hybrid density functional-Hartree-Fock formulations. The results suggest that fluorite TiO2 is a highly incompressible solid with a large bulk modulus value (K(0) approximately 395 GPa), approaching that of ultrahard cotunnite TiO2 (K(0)=431 GPa). The bulk modulus obtained for pyrite TiO2 is considerably smaller (K(0) approximately 220-260 GPa), nonetheless larger than the value determined experimentally for cubic TiO2. Calculated shear modulus values indicate that fluorite TiO2 has the potential to be an ultrahard material, if it could be stabilized under ambient conditions.
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