Tailoring Optical and Magnetic Properties in Mn2+-Substituted 2D Magnetic Semiconductor SnS2: A Powder XRD Approach for Electronic Structure Analysis

Abstract

A single-phase, two-dimensional layered semiconductor of Mn²⁺-substituted SnS₂ was synthesized using the low temperature and cost-effective hydrothermal method. Powder X-ray diffraction (XRD) analysis revealed a considerable contribution of γ-MnO₂ at higher Mn²⁺ substitution concentrations. An XRD blue shift accounts for Mn²⁺ substitutions at both substitutional and interstitial sites. Scanning electron microscope (SEM) analysis confirms a two-dimensional disk morphology, containing a large number of nano-crystallites. The electronic structure is visualized using the 3D, 2D, and 1D maximum entropy method (MEM) analysis, such as electron density inside the unit cell, the type and strength of inter- and intra-bonding, and its effect on Mn²⁺ substitution. In addition to substitutional doping, MEM-based peak search analysis and electron paramagnetic resonance (EPR) studies confirmed interstitial charge accumulation. The 3% Mn²⁺-substituted composition has superior soft ferromagnetism, with a magnetic saturation of 0.1915 emu/g and coercivity of 174.16 Oe, making it suitable for dilute magnetic semiconductor applications. The mechanism and origin of ferromagnetism are explained based on Mn²⁺ substitution in substitutional or interstitial sites as well as the concentration of impurity addition γ-MnO₂. Optical energy band gap analysis confirms that direct energy gaps are useful for photoactivated catalytic applications. An empirical correlation between magnetic saturation and MEM-based electronic structure is the highlight of the research.