Tahani Saad Almutairi
ZnMn2O4 has attracted increasing attention as a multifunctional spinel oxide owing to its structural flexibility and relevance in energy-related applications. Its physical properties are governed by the interplay between cation distribution and magnetic ordering, which strongly influence lattice distortion and vibrational behavior. In this work, hybrid density functional theory is employed to systematically investigate the structural stability, magnetic configurations, and Raman-active lattice dynamics of ZnMn2O4 for different inversion degrees (X = 0, 0.5, 1) under ferromagnetic (FM) and antiferromagnetic (AFM) ordering. For the tetragonal phase, all symmetry-allowed Raman-active modes are identified, consistent with group-theoretical predictions. For the ground-state normal configuration (X = 0), the energy difference between FM and AFM states is small (∼0.051 eV), yet distinct spin-dependent effects are observed in the Raman spectra. Midfrequency modes exhibit systematic frequency shifts of 7-15 cm-1 between the two magnetic configurations, with modes near 327 and 378 cm-1 shifting to 334 and 363 cm-1 in the AFM state. These changes are accompanied by notable intensity variations, including an increase of approximately 30% for the latter mode. These results demonstrate that specific Raman modes are intrinsically sensitive to magnetic ordering and can serve as direct spectroscopic markers of spin alignment. Overall, this study reveals a strong coupling between magnetic configuration, cation distribution, and lattice dynamics in ZnMn2O4, providing new insights into the design and characterization of spinel oxides.