Influence of the Hubbard U Correction on the Electronic Properties and Chemical Bands of the Cubic (Pm𝟑̲ m) Phase of SrTiO3 Using GGA/PBE and LDA/CA-PZ Approximations

Journal Article (2024)
Author(s)

I. Derkaoui (University Sidi Mohammed Ben Abdellah)

Mohamed Achehboune (University of Namur)

Roberts I. Eglitis (University of Latvia)

Anatoli I. Popov (University of Latvia)

Issam Boukhoubza (University Sidi Mohammed Ben Abdellah)

Mohamed A. Basyooni-M.Kabatas (Selçuk University, TU Delft - Dynamics of Micro and Nano Systems, National Research Institute of Astronomy and Geophysics)

Abdellah Rezzouk (University Sidi Mohammed Ben Abdellah)

Research Group
Dynamics of Micro and Nano Systems
DOI related publication
https://doi.org/10.3390/molecules29133081
More Info
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Publication Year
2024
Language
English
Research Group
Dynamics of Micro and Nano Systems
Issue number
13
Volume number
29
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Abstract

By using DFT simulations employing the GGA/PBE and LDA/CA-PZ approximations, the effects of the Hubbard U correction on the crystal structure, electronic properties, and chemical bands of the cubic phase (Pm3̲m) of STO were investigated. Our findings showed that the cubic phase (Pm3̲m) STO’s band gaps and lattice parameters/volume are in reasonably good accordance with the experimental data, supporting the accuracy of our model. By applying the DFT + U method, we were able to obtain band gaps that were in reasonably good agreement with the most widely used experimental band gaps of the cubic (Pm3̲m) phase of STO, which are 3.20 eV, 3.24 eV, and 3.25 eV. This proves that the Hubbard U correction can overcome the underestimation of the band gaps induced by both GGA/PBE and LDA/CA-PZ approximations. On the other hand, the Sr-O and Ti-O bindings appear predominantly ionic and covalent, respectively, based on the effective valence charges, electron density distribution, and partial density of states analyses. In an attempt to enhance the performance of STO for new applications, these results might also be utilized as theoretical guidance, benefitting from our precise predicted values of the gap energies of the cubic phase (Pm3̲m).