Structural and electronic properties of rare-earth chromites: A computational and experimental study

• Published in: Physical review. B 2022-10, Vol.106 (16), Article 165117
• Main Authors: Shi, Jianhang, Fernando, Gayanath W., Dang, Yanliu, Suib, Steven L., Jain, Menka
• Format: Article
• Language: English
• Subjects: chemical bonding; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; density of states; electronic structure; structural properties
• ISSN: 2469-9950; 2469-9969
• DOI: 10.1103/PhysRevB.106.165117

Here, in this work, the structural, optical, and electronic properties of rare-earth perovskites of the general formula R⁢CrO3, where R⁢ represents the rare-earth Gd, Tb, Dy, Ho, Er, and Tm, have been studied in detail. These compounds were synthesized through a facile citrate route. X-ray diffraction, Raman spectroscopy, and UV-Visible spectroscopy were utilized to reveal the structural evolutions in R⁢⁢CrO3. The lattice parameters, Cr3+–O2–Cr3+ bond angle, and CrO6 octahedral distortions were found to strongly depend on the ionic radii of R⁢. First-principles calculations based on density-functional theory within the generalized gradient approximation (GGA) of Perdew-Burke-Ernzerhof (PBE) and strongly constrained and appropriately normed (SCAN) meta-GGA were also employed to calculate the structural and electronic properties of R⁢⁢CrO3. The ground-state energy, lattice constants, electronic structures, and density of states of R⁢⁢CrO3 were calculated. These provide some insights into the electronic characteristics of the R⁢⁢CrO3 compounds. The calculated values of lattice parameters and band gaps with Hubbard U correction (SCAN+U) agree well with values measured experimentally and show more accuracy in predicting the ground-state crystal structure and band structure compared to PBE+U approximation. The band gap of R⁢⁢CrO3 is found to be independent of the ionic radii of R⁢ from both experiments and calculations.