Derkaoui Issam, Achehboune Mohamed, Eglitis Roberts I, Popov Anatoli I, Rezzouk Abdellah
Laboratory of Solid State Physics, Faculty of Sciences Dhar El Mahraz, University Sidi Mohammed Ben Abdellah, P.O. Box 1796, Fez 30000, Morocco.
Laboratoire de Physique du Solide, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
Materials (Basel). 2023 Jun 10;16(12):4302. doi: 10.3390/ma16124302.
We have performed a systematic study resulting in detailed information on the structural, electronic and optical properties of the cubic (m3¯m) and tetragonal (4mm) phases of PbTiO applying the GGA/PBE approximation with and without the Hubbard U potential correction. Through the variation in Hubbard potential values, we establish band gap predictions for the tetragonal phase of PbTiO that are in rather good agreement with experimental data. Furthermore, the bond lengths for both phases of PbTiO were assessed with experimental measurements, confirming the validity of our model, while chemical bond analysis highlights the covalent nature of the Ti-O and Pb-O bonds. In addition, the study of the optical properties of the two phases of PbTiO, by applying Hubbard' U potential, corrects the systematic inaccuracy of the GGA approximation, as well as validating the electronic analysis and offering excellent concordance with the experimental results. Therefore, our results underline that the GGA/PBE approximation with the Hubbard U potential correction could be an effective method for obtaining reliable band gap predictions with moderate computational cost. Therefore, these findings will enable theorists to make use of the precise values of these two phases' gap energies to enhance PbTiO's performance for new applications.
我们进行了一项系统研究，利用有和没有哈伯德U势校正的GGA/PBE近似，得出了关于立方相（m3¯m）和四方相（4mm）PbTiO的结构、电子和光学性质的详细信息。通过改变哈伯德势值，我们对PbTiO四方相的带隙预测与实验数据相当吻合。此外，通过实验测量评估了PbTiO两相的键长，证实了我们模型的有效性，而化学键分析突出了Ti-O键和Pb-O键的共价性质。此外，通过应用哈伯德U势对PbTiO两相的光学性质进行研究，校正了GGA近似的系统误差，验证了电子分析，并与实验结果高度一致。因此，我们的结果强调，带有哈伯德U势校正的GGA/PBE近似可能是一种以适度计算成本获得可靠带隙预测的有效方法。因此，这些发现将使理论学家能够利用这两个相的能隙能量的精确值来提高PbTiO在新应用中的性能。
