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

In this work, the structural, optical, and electronic properties of rare-earth perovskites general formula $R{\mathrm{CrO}}_{3}$, where $R$ represents Gd, Tb, Dy, Ho, Er, Tm, have been studied in detail. These compounds were synthesized through a facile citrate route. X-ray diffraction, Raman spectroscopy, UV-Visible spectroscopy utilized to reveal structural evolutions $R{\mathrm{CrO}}_{3}$. The lattice parameters, ${\mathrm{Cr}}^{3+}--{\mathrm{O}}^{2}--{\mathrm{Cr}}^{3+}$ bond angle, ${\mathrm{CrO}}_{6}$ octahedral distortions found strongly depend on ionic radii $R$. First-principles calculations based density-functional theory within generalized gradient approximation (GGA) Perdew-Burke-Ernzerhof (PBE) constrained appropriately normed (SCAN) meta-GGA also employed calculate ground-state energy, constants, structures, density states $R{\mathrm{CrO}}_{3}$ calculated. provide some insights into characteristics compounds. calculated values parameters band gaps with Hubbard $U$ correction ($\mathrm{SCAN}+U$) agree well measured experimentally show more accuracy predicting crystal structure compared $\mathrm{PBE}+U$ approximation. gap is be independent from both experiments calculations.