First-principles study of elastic properties of CeO2, ThO2 and PoO2

• Published in: Journal of physics. Condensed matter 2006-10, Vol.18 (42), p.9615-9624
• Main Authors: Kanchana, V, Vaitheeswaran, G, Svane, A, Delin, A
• Format: Article
• Language: English
• Subjects: ab-initio; bulk modulus; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; debye temperature; doped ceria; Elasticity, elastic constants; Electron density of states and band structure of crystalline solids; Electron states; electronic-structure; Exact sciences and technology; fluorite structure; induced phase-transformation; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Other inorganic compounds; Physics; pressure; thermal-expansion; x-ray-absorption
• ISSN: 0953-8984; 1361-648X; 1361-648X
• DOI: 10.1088/0953-8984/18/42/008

Using first-principles density functional calculations, the structural and elastic properties of fluorite type oxides CeO2, ThO2 and PoO2 were studied by means of the full-potential linear muffin-tin orbital method. Calculations were performed within the local density approximation (LDA) as well as generalized gradient approximation (GGA) to the exchange correlation potential. The calculated equilibrium lattice constants and bulk moduli are in good agreement with the experimental results, as are the computed elastic constants for CeO2 and ThO2. For PoO2 this is the first quantitative theoretical prediction of the ground state properties, and it still awaits experimental confirmation. The calculations find PoO2 to be a semiconductor with an indirect band gap and elastic constants similar in magnitude to those of CeO2 and ThO2.