Synthesis, growth, and structural, optical, mechanical, electrical properties of a new inorganic nonlinear optical crystal: Sodium manganese tetrachloride (SMTC)

Abstract

Please cite this article in press as: M. Packiya raj, et al. Synthesis, growth, and structural, optical, mechanical, electrical properties of a new inorganic nonlinear optical crystal: Sodium manganese tetrachloride (SMTC), J. Taibah Univ. Sci. (2015), http://dx. AbstractA new inorganic nonlinear optical single crystal of sodium manganese tetrachloride (SMTC) has been successfully grown from aqueous solution using the slow evaporation technique at room temperature. The crystals obtained using the aforementioned method were characterized using different techniques. The crystalline nature of the as-grown crystal of SMTC was analyzed using powder X-ray diffraction. Single-crystal X-ray diffraction revealed that the crystal belongs to an orthorhombic system with noncentrosymmetric space group Pbam. The optical transmission study of the SMTC crystal revealed high transmittance in the entire UV-vis region, and the lower cut-off wavelength was determined to be 240 nm. The mechanical strength of the as-grown crystal was estimated using the Vickers microhardness test. The second harmonic generation (SHG) efficiency of the crystal was measured using Kurtz's powder technique, which indicated that the crystal has a nonlinear optical (NLO) efficiency that is 1.32 times greater than that of KDP. The dielectric constant and dielectric loss of the compound were measured at different temperatures with varying frequencies. The photoconductivity study confirmed that the title compound possesses a negative photoconducting nature. The growth mechanism and surface features of the as-grown crystals were investigated using chemical etching analysis.

Comments on the Paper: “Synthesis, Growth and Optical, Mechanical, Electrical and Surface Properties of an Inorganic New Nonlinear Optical Crystal: Sodium Cadmium Tetra Chloride (SCTC)”

“…The same group has published a paper on a so‐called SMTC crystal by the solution method, which was obtained by taking NaCl and MnCl 2 in 2:1 ratio in water. [ 2 ] According to authors, the unit cell of SMTC which is supposed to be a new NLO crystal, is in agreement with the unit cell of Na 2 MnCl 4 which is another double halide in the Sr 2 PbO 4 ‐type structure reported by Goodyear et al. [ 12 ] In this context, the following statement from the paper of Goodyear et al.…”

“…A scrutiny of the publication revealed several inconsistencies in the scientific claims, which are described next. The same research group published a paper [ 2 ] on another so‐called sodium manganese tetra chloride (SMTC) crystal. Several scientific inaccuracies are also noted in this paper.…”

“…However, Packiyaraj et al. [ 2 ] do not give any explanation whatsoever as to how they could isolate such a moisture‐sensitive solid from an aqueous solution under the name SMTC. No single crystal refinement result other than the unit cell is given.…”

Comprehensive Studies on Amino Acid Based Organometallic L-Threoninum Cobalt (Ii) Sulfate (Ltcs) Single Crystal

“…It was observed that with an increase in frequency, the AC conductivity was slowly rising up to 100 kHz and a rapid linear increase thereafter. This study unambiguously identifies the grown crystal is less defective, good quality material [30,31]. 5.…”

Synthesis, Growth and Optical, Mechanical, Electrical and Surface Properties of an Inorganic New Nonlinear Optical Crystal: Sodium Cadmium Tetra Chloride (SCTC)

“…To overcome this kind of problems, new types are called inorganic crystals are developing now days. Inorganic NLO crystals typically have high melting point, excellent mechanical behaviour, high thermal stability and high degree of chemical inertness …”