Maximum entropy reconstruction of electronic structure in (Fe Ni) co-substituted SnS2 nano-discs exhibiting tunable optical and magnetic properties

High-purity, nano-disc-shaped, two-dimensional dilute magnetic semiconductors of Fe and Ni co-substituted SnS 2 with compositions Sn 1-x Fe x/2 Ni x/2 S 2 (x = 0.03, 0.06, 0.09) were prepared using hydrothermal crystallization. XRD confirmed a hexagonal SnS 2 structure indexed to the P 3 ¯ m1 space group with a shoulder at (001) for x = 0.09, reflecting 9 % substitutional solubility limit. ESR spectra revealed Fe 3+ , Ni 2+ , and Ni 3+ oxidation states. Room temperature magnetic measurements showed moderate magnetic saturation of 0.0408 and 0.0804 emu/g for x = 0.03 and 0.06, respectively, along with high coercivities of 1474.3 and 677.28 Oe. Optical analysis showed bandgap tuning from 1.298 eV to 2.796 eV by increasing the dopant concentration, making it useful for applications like solar cells, photodetectors, photocatalysts, and sensors. HRTEM, SAED, and EDX confirmed a polycrystalline nano-disc shape with evenly distributed elements. Electronic structural analysis revealed electron density distribution, bonding and interstitial charge accumulation. • Fe/Ni co-substituted SnS 2 nano-discs synthesized via hydrothermal crystallization. • Shoulder at (001) for x = 0.09 indicates 9 % substitutional solubility limit in SnS 2 . • Stable magnetism with high coercivity and low magnetization for memory applications. • Tunable bandgap from UV to NIR via doping for multifunctional device applications.