Assessing thermochemical properties of materials through ab initio quantum-mechanical methods: the case of α-Al2O3
| العنوان: | Assessing thermochemical properties of materials through ab initio quantum-mechanical methods: the case of α-Al2O3 |
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| المؤلفون: | Alessandro Erba, Jefferson Maul, Roberto Dovesi, Raffaella Demichelis |
| المصدر: | Physical Chemistry Chemical Physics. 17:11670-11677 |
| بيانات النشر: | Royal Society of Chemistry (RSC), 2015. |
| سنة النشر: | 2015 |
| مصطلحات موضوعية: | Bulk modulus, Physical and Theoretical Chemistry, Physics and Astronomy (all), Chemistry, Ab initio, General Physics and Astronomy, Thermodynamics, Atmospheric temperature range, Thermal expansion, Melting point, Physical chemistry, Density functional theory, Material properties, Basis set |
| الوصف: | The thermochemical behavior of α-Al2O3 corundum in the whole temperature range 0-2317 K (melting point) and under pressures up to 12 GPa is predicted by applying ab initio methods based on the density functional theory (DFT), the use of a local basis set and periodic-boundary conditions. Thermodynamic properties are treated both within and beyond the harmonic approximation to the lattice potential. In particular, a recent implementation of the quasi-harmonic approximation, in the Crystal program, is here shown to provide a reliable description of the thermal expansion coefficient, entropy, constant-volume and constant-pressure specific heats, and temperature dependence of the bulk modulus, nearly up to the corundum melting temperature. This is a remarkable outcome suggesting α-Al2O3 to be an almost perfect quasi-harmonic crystal. The effect of using different computational parameters and DFT functionals belonging to different levels of approximations on the accuracy of the thermal properties is tested, providing a reference for further studies involving alumina polymorphs and, more generally, quasi-ionic minerals. |
| تدمد: | 1463-9084 1463-9076 |
| DOI: | 10.1039/c5cp01537e |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e5f9227007c23daab0218023b85d23fe https://doi.org/10.1039/c5cp01537e |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....e5f9227007c23daab0218023b85d23fe |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14639084 14639076 |
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| DOI: | 10.1039/c5cp01537e |