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

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.

FIRST-PRINCIPLE MODELING OF STRUCTURAL, ELECTRONIC, AND OPTICAL PROPERTIES OF CH3NH3PbBr3

“…The bottom of the conduction band is mainly formed by the 3d and 4d states of Ti and Nb atoms, respectively (figure 3). In general, the obtained distribution of the density of states corresponds to previous theoretical calculations [16], and we also see a good agreement with the results obtained separately for components of the PMN-PT solid solution [33,34]. The next stage of our investigation was based on analyzing the genesis of the electronic states and their energy position and selecting the Hubbard 𝑈 parameters to obtain more accurate electronic structures for the 0.75PMN-0.25PT system.…”

“…PDOS shows that deep electronic states from −18 to −15 eV energy range are mainly derived from O 2s-orbitals and Pb 5d-orbitals. Similar behavior was inherent to the PDOS of PbTiO 3 perovskites [33].…”

“…To improve the obtained results, in addition to the 𝑈 𝑑,Ti , and 𝑈 𝑑,Nb parameters, the non-zero 𝑈 parameter for oxygen atoms (𝑈 𝑝,O ) was taken into account. This approach was used for simple oxide semiconductors (TiO 2 , ZnO) [35][36][37][38], and for perovskite-type ABO 3 oxide crystals, particularly for PbTiO 3 [33] and BaTiO 3 [39]. The obtained results for different sets of 𝑈 parameters are presented in table 2.…”

Segregation and interdiffusion processes in perovskites: a review of recent advances

“…[9][10][11][12] Perovskites represent a unique class of materials with multifunctional properties that make them an attractive object of study for researchers worldwide. 13,14 The potential applications of perovskite are diverse and include use in sensors and catalyst electrodes, certain types of fuel cells, 15 solar cells, [16][17][18] lasers, 19,20 storage devices, 21 photocatalysis devices, 22 and other applications. The A-sublattice typically includes various metals such as alkali, alkaline earth, rare earth, and others.…”

Reuse and Mechanochemical Processing of Ore Dressing Tailings Used for Extracting Pb and Zn

“…This system of measures is primarily aimed at optimizing material flows based on their cyclicity at all stages of production [36][37][38][39][40]. Another approach within the framework of the "circularity" concept is the re-extraction of metals from technogenic raw materials of old tailings [41,42] or after the direct formation of enrichment tailings [43][44][45], ash residue of solid household waste [46], and the reuse of various kinds of waste [47][48][49].…”