Synthesis and Characterization of Semi-Organic Sodium Thiocyanate Potassium Sulphate (STPS) Crystal using Slow Evaporation Method

Abstract

In recent times, the Semi-organic crystals have high impact over optical communication, laser technology and electro-optic modulation, with its consumption of versatile Nonlinear Optical (NLO) application. many efforts have been taken by the researchers to synthesize crystals with better optical nonlinearity and stability. Conventional techniques for growing single crystals often suffer from defects such as impurities and dislocations, which compromise the electrical and structural stability of the crystals. Furthermore, non-uniform growth conditions hinder the repeatability and reliability of these methods in specific applications. The primary aim of this research is to synthesize and investigate the growth and development of a highly proficient nonlinear semi-organic crystal known as Sodium Thiocyanate Potassium Sulphate (STPS). The STPS crystal is grown using a slow solvent evaporation method at ambient temperature, employing double-deionized water as the solvent. Extensive characterization of the STPS crystal is conducted using various techniques: X-ray diffraction (XRD) provides insights into the crystal structure and atomic plane spacing, Fourier-transform infrared spectroscopy (FTIR) identifies functional groups, UV-Vis spectroscopy reveals electronic transitions, scanning electron microscopy (SEM) detects material flaws, and microhardness testing verifies the crystal quality. The STPS crystal exhibits a microhardness value of 30.01, indicating significant mechanical strength. The UV-Vis-NIR investigations demonstrate that the STPS crystal has high optical quality, with 100% transmittance in the visible region and a cutoff wavelength below 250 nm, making it suitable for second harmonic generation (SHG) applications. Additionally, the STPS crystals display notable antibacterial properties, suggesting potential applications in medicinal fields. The comprehensive characterization confirms the improved structure and properties of the synthesized STPS crystals, highlighting their potential for advanced photonic and antimicrobial applications.