Haiqing Sun

Preparation and Characterization of Nonlinear Optical Crystal Materials: Cadmium Mercury Thiocyanate and its Lewis Base Adducts

Cadmium mercury thiocyanate (CdHg(SCN) 4 , CMTC) and its two lewis base adducts: cadmium mercury thiocyanate dimethyl-sulphoxide (CdHg(SCN) 4 (H 6 C 2 OS) 2 , CMTD) and cadmium mercury thiocyanate glycol monomethyl ether (CdHg(SCN) 4 (C 3 H 8 O 2 ), CMTG) have been discovered as nonlinear optical (NLO) crystal materials. Their structural, optical and physicochemical properties were characterized by X-ray powder diffraction (XRPD), infrared spectroscopy, vis/UV/NIR spectra and thermal analysis. It is discovered that their transparency cutoffs lie in the UV region and CMTD crystals possess the shortest cutoff wavelength among the three crystal materials.

Physicochemical behavior of nonlinear optical crystal CdHg(SCN)4

Abstract The preparation and purification of cadmium mercury thiocyanate, CdHg(SCN)4 (CMTC) are described. The identity of the synthesized compound was characterized by Raman, infrared and X-ray powder diffraction spectra. The thermal stability and thermal decomposition of CMTC crystals were investigated by means of thermogravimetric analysis and differential scanning calorimetry. The impurities in the growth solutions and their effects are discussed.

Growth morphology and thermal properties of the organometallic nonlinear optical crystal: MnHg(SCN)4(C2H6OS)2

Abstract Manganese mercury thiocyanate-bis(dimethyl sulfoxide) MnHg(SCN) 4 (C 2 H 6 OS) 2 (MMTD) single crystals of optical quality have been grown from solution by the slow temperature-lowering method. The X-ray powder diffraction (XRPD) spectroscopy of MMTD crystal was performed at room temperature. The morphology of the crystal was indexed. The thermal decomposition process is characterized by differential scanning calorimetry (DSC). The specific heat of the crystal is 699.5 J mol −1 K −1 at 300 K. The thermal expansion coefficient (TEC) along the a -, b - and c -axis is α 1 =5.33×10 −5 , α 2 =4.51×10 −5 and α 3 =3.10×10 −5 /K, respectively. All the TECs are positive and interpreted on the basis of crystal structure.

Cadmium mercury seleno­cyanate, CdHg(SeCN)4

CdHg(SeCN)4 has an extended three-dimensional network structure in which the slightly distorted CdN4 and HgSe4 tetrahedra are connected by –SeCN– bridges.