Estudo das propriedades estruturais e eletrônicas do espodumênio (LiAlSi2O6) em diferentes fases monoclínicas

Abstract

This work investigates the structural and electronic properties of spodumene (LiAlSi2O6), an insulating material of great technological relevance, widely used in the ceramic industry, glassmaking, lithium extraction, luminescent applications, and gemology. Under ambient conditions, spodumene crystallizes in the monoclinic (α) phase; however, under high temperatures and ambient pressure, it can exhibit structural transitions to the tetragonal (β) or hexagonal (γ) phases, with the β phase being the thermodynamically more stable. In this study, through computational simulations based on Density Functional Theory, the structural and electronic properties of two different monoclinic phases with space groups P21/c and C2/c are analyzed and compared. Aiming to correct the underestimation of the characteristic energy gap of the Generalized Gradient Approximation (GGA), observed in previous studies, the modified Becke-Johnson potential (mBJ) is employed, which provides a more accurate description of the electronic properties of solids. The simulations were performed using the WIEN2k computational package, based on the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method, recognized for its high accuracy in electronic structure calculations. The results obtained are compared with data available in the literature, contributing to a better understanding of the electronic behavior of spodumene and providing support for future experimental investigations and technological applications of this material.