Crystal Structure, Thermal Stability, Supercapacitor, and Nonlinear Optical Behavior in β-Alanine Sodium Nitrate Crystals

Abstract

β-Alanine sodium nitrate mixed single crystals were successfully grown using the slow evaporation solution growth technique and systematically examined for multifunctional applications. Single-crystal X-ray diffraction analysis confirmed the crystalline nature, phase purity, and good structural perfection of the grown crystals. FTIR spectroscopy was used to identify the characteristic vibrational frequencies corresponding to the functional groups present in the crystal lattice. The elemental composition and chemical purity were validated through Energy Dispersive X-ray Analysis (EDAX). Scanning electron microscopy revealed well-defined crystalline morphology with smooth facets and uniform distribution, indicating high crystal quality and the absence of significant surface defects. Optical properties were investigated using UV–Vis–NIR spectroscopy, and the optical band gap was determined. The observed wide band gap confirms the suitability of the material for optoelectronic device applications. Thermal stability was assessed by thermogravimetric analysis (TGA) and differential thermal analysis (DTA), showing stability up to 150°C. Electrochemical studies demonstrated high specific capacitance with stable charge–discharge behavior. Third-order nonlinear optical parameters (χ3, n2, and β), determined using the Z-scan technique, revealed a strong nonlinear response and effective optical limiting behavior, highlighting the potential of β-alanine sodium nitrate crystals for optoelectronic, energy storage, and nonlinear photonic applications.