Temperature dependence on phase evolution in the BaTiO3 polytypes studied using ab initio calculations |
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| Authors: | Marisa C. Oliveira Renan A. P. Ribeiro Elson Longo Maurício R. D. Bomio Fabiana V. Motta Sergio R. de Lazaro |
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| Affiliation: | 1. LSQM – Laboratory of Chemical Synthesis of Materials, Department of Materials Engineering, Federal University of Rio Grande do Norte, Natal, Brazil;2. CDMF-UFSCar, Federal University of São Carlos, São Carlos, Brazil;3. Department of Chemistry, State University of Ponta Grossa, Ponta Grossa, Brazil |
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| Abstract: | Identifying the forces that drive a temperature-induced phase transition is always challenging in the prospect of the first-principles methods. Herein, we perform a first-principles study of the temperature effects on structural, energetic, electronic, and vibrational properties of four BaTiO3 polymorphs using quasi-harmonic approximations. Study of the stability between these four phases, which we break into contributions arising from the vibration of the lattice, electronic structure, and volume expansion/contraction, is helpful to confirm the sequence of phase transitions as cubic → tetragonal → orthorhombic → rhombohedral, as well as its transition temperatures. A general mechanism was proposed based on the combination between structural distortions at [TiO6] clusters, vibrational characteristics, and electronic structure. These findings confirm the power of quasi-harmonic approximations to disclose the main fingerprints associated with both thermic and mechanical phase transitions, serving as a guide for further theoretical studies. |
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| Keywords: | BaTiO3 DFT phase transition temperature-dependent BTO |
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