Overview of the Structural, Electronic and Optical Properties of the Cubic and Tetragonal Phases of PbTiO3 by Applying Hubbard Potential Correction

Issam Derkaoui; Mohamed Achehboune; Roberts I Eglitis; Anatoli I Popov; Abdellah Rezzouk

doi:10.3390/ma16124302

Overview of the Structural, Electronic and Optical Properties of the Cubic and Tetragonal Phases of PbTiO₃ by Applying Hubbard Potential Correction

Materials (Basel). 2023 Jun 10;16(12):4302. doi: 10.3390/ma16124302.

Authors

Issam Derkaoui¹, Mohamed Achehboune², Roberts I Eglitis³, Anatoli I Popov³, Abdellah Rezzouk¹

Affiliations

¹ Laboratory of Solid State Physics, Faculty of Sciences Dhar El Mahraz, University Sidi Mohammed Ben Abdellah, P.O. Box 1796, Fez 30000, Morocco.
² Laboratoire de Physique du Solide, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles 61, 5000 Namur, Belgium.
³ Institute of Solid State Physics, University of Latvia, 8 Kengaraga Str., LV1063 Riga, Latvia.

Abstract

We have performed a systematic study resulting in detailed information on the structural, electronic and optical properties of the cubic (Pm3¯m) and tetragonal (P4mm) phases of PbTiO₃ 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 PbTiO₃ that are in rather good agreement with experimental data. Furthermore, the bond lengths for both phases of PbTiO₃ 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 PbTiO₃, 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 PbTiO₃'s performance for new applications.

Keywords: GGA+U; Hubbard correction; PbTiO3; chemical bonds; electronic properties; optical properties.

Grants and funding

ISSP UL as the Center of Excellence is supported through the Framework Program for European universities, Union Horizon 2020, H2020-WIDESPREAD-01–2016–2017-TeamingPhase2, under Grant Agreement No. 739508, CAMART2 project.