Optimization of Electronic Structure in Cr-Doped α-Al₂O₃ Using First-Principles Methods

This study focuses on the optimization of the electronic properties of Cr-doped α-Al₂O₃, a material critical for optoelectronic and high-pressure applications, using first-principles calculations within the density functional theory (DFT) framework. The full-potential linearized augmented plane wave (FP-LAPW) method was employed, comparing generalized gradient approximation (GGA), local spin density approximation (LSDA), and LSDA+U approaches. The LSDA+U method provided the most effective optimization, accurately reproducing the transition energy from Cr impurity states to the conduction band, closely aligning with experimental values, whereas GGA and LSDA underestimated these energies. By integrating structural relaxation, magnetic property analysis, and optical transition evaluations, this work highlights the pivotal role of optimization in achieving precise electronic structures, offering valuable insights for designing advanced materials.