Investigation of the Structural, Mechanical, Thermal, and Magneto-Electronic Properties of Promising Ferrite Spinel Oxides XFe2O4 (X = Ge and Sm): A First-Principle Approach

This study employs first-principles computations to analyze ferrite spinels GeFe₂O₄ and SmFe₂O₄ using density functional theory (DFT). Structural stability calculations reveal that GeFe₂O₄ favors an antiferromagnetic phase, while SmFe₂O₄ stabilizes in a ferrimagnetic phase. Both compounds are elastically stable and ductile, and exhibit lattice constants consistent with experimental values, validating the reliability of the calculations. A significant drop in Debye temperature (from 495 to 233 K) occurs when Ge is replaced by Sm, while high melting temperatures indicate thermal stability over broad temperature ranges. The spin-polarized electronic band structure confirms the metallic nature of both materials. Furthermore, the Curie temperature and magnetic moment of SmFe₂O₄, calculated using Generalized Gradient Approximation (GGA + U) and the Heyd–Scuseria–Ernzerhof (HSE) methods, underline its potential for spintronic applications.