CMTD晶体的分解过程原子力显微镜实时观测研究

用原子力显微镜实时观测了有机晶体CMTD(CdHg(SCN)4(H6C2OS)2)的表面分解过程,这一分解过程是以表面形貌变化来表征的,并且能反映分解过程中的一些固态反应的物理一化学变化机制.X射线能谱分析(EDAX)表明,相对于新鲜的CMTD晶体,在分解物中Hg低而S高;X射线衍射(XRD)表明分解物为非晶态;红外吸收光谱(IR)表明在CMTD晶体结构中的(H6C2OS)结构基元被分解为H2O和酸;量热分析(DSC)表明CMTD晶体在室温空气中确实有化学反应发生.本文用原子力显微镜实时记录了这一分解过程的形貌变化,发现这种非晶态的分解物的产生过程为:成核一核生长一核分散等.这是首次用原子力显微镜实时观测到这种分解过程.

Decomposition Processes of CMTD Crystals in situ Observation by AFM

The decomposition processes of CMTD(CdHg(SCN)_4(H_6C_2OS)_2)crystal surface were investigated by AFM(atomic force microscopy).These processes are characterized by the morphological changes of the surface and reflect some physic-chemical mechanism of the solid-state reaction.EDAX(energy dispersion analyzer of X-ray)shows that Hg is poorer but S is richer in the decomposition products than in fresh CMTD crystals.XRD(X-ray diffraction)data reflect that the decomposition products are non-crystalline.IR(infrared ray absorbed spectra)analysis shows that during the decomposition processes(H_6C_2OS)units were decomposed into H_2O and acid.DSC(differential scanning calorimeter)analysis shows that CMTD crystals have chemical reactions in air at room temperature.AFM observations show that the formation processes of the non-crystalline decomposition products include nucleation,nuclei growth,nuclei dispersion,etc.It is the first time to directly observe this kind of decomposition processes by AFM.