LAUSR

Abstract The persistent phosphorus LiGa5O8:Cr3+ has attracted considerable attention due to its application in biomedical images. In this work, we used ab initio calculations based on density functional theory to study the properties of this compound doped with Cr3+. Two types of calculations are considered: (1) Cr3+ impurity replacing the Ga3+ atom at the 8c site and (2) Cr3+ impurity replacing the Ga3+ atom at the 12d site. From these calculations, we determine the structural, electronic, energetic, and magnetic properties for LiGa5O8:Cr3+. The generalized gradient approximation GGA-PBEsol functional, and the modified Becke-Johnson potential were used to simulate the exchange and correlation effects. The result for the defect forming energy revealed that the Cr3+ impurity is preferred to occupy the 12d site of Ga3+. From the Bader analysis, it was possible to determine the dopant defect charge when inserted into the host matrix of LiGa5O8. Through the density of the state, it was determined that the valence electron configuration of the Cr3+ dopant is 4s0 3d3 (8c or 12d site). There is a magnetic moment in the unit cell of −3.0μB due to the presence of Cr3+ in the LiGa5O8 lattice.