Comparative analysis on microhardness and third order nonlinear optical traits of pure and Nd³⁺ doped zinc tris-thiourea sulphate (ZTS) crystal

Present investigation is aimed to explore the single crystal growth, microhardness and third order nonlinear optical (TONLO) properties of Nd³⁺ doped zinc tris-thiourea sulphate (ZTS) crystal. The commercial slow solvent evaporation technique has been chosen to grow a good quality ZTS (12 mm × 0.5 mm × 0.3 mm) and Nd³⁺ doped ZTS (11 mm × 0.6 mm × 0.4 mm) single crystals. Vickers microhardness test has been employed to analyze the influence of Nd³⁺ dopant on the hardness behavior of ZTS single crystal. The TONLO effects occurring in Nd³⁺ doped ZTS single crystal have been evaluated by means of Z-scan technique using a He–Ne laser operating at 632.8 nm. The close and open aperture Z-scan configuration have been used to determine the nature of TONLO refraction n₂ and absorption β, respectively. The magnitudes of vital TONLO parameters, such as refraction n₂, absorption coefficient β, figure of merit and susceptibility χ³ of the Nd³⁺ doped ZTS single crystal, have been determined using Z-scan transmittance data. The n₂, β, and χ³ of Nd³⁺ doped ZTS single crystal were found to be of the order of 10⁻¹⁰ cm²/W, 10⁻⁶cm/W and 10⁻⁵ esu, respectively.