Solvothermal synthesis of well-dispersed MF2 (M = Ca,Sr,Ba) nanocrystals and their optical properties
Solvothermal synthesis of well-dispersed MF2 (M = Ca,Sr,Ba) nanocrystals and their optical properties
复制标题
DOI：
10.1088/0957-4484/19/7/075603
复制
发表时间：
2008-01
期刊：
影响因子：
3.5
通讯作者：
Xiaomin Zhang;Z. Quan;Jun Yang;Piaoping Yang;Hongzhou Lian;Jun Lin
中科院分区：
文献类型：
--
作者：
Xiaomin Zhang;Z. Quan;Jun Yang;Piaoping Yang;Hongzhou Lian;Jun Lin
采用溶剂热法在油酸存在下合成了MF2 （M = Ca,Sr,Ba）纳米晶体（NCs），并分别用x射线衍射（XRD）、透射电子显微镜（TEM）、傅里叶变换红外（FT-IR）光谱、紫外/可见吸收光谱、光致发光（PL）激发和发射光谱以及寿命对其进行了表征。在合成过程中，油酸作为表面活性剂对MF2 NCs的生长和溶解度起着至关重要的作用。制备的CaF2、SrF2和BaF2纳米碳纳米管分别呈截断八面体、立方体和片状，分布较窄。提出了可能的生长机制来解释这些结果。制备的纳米碳化物具有较高的结晶性，在环己烷中分散良好，形成稳定、透明的胶体溶液，与环己烷溶剂相比，在400 nm的光致发光（PL）光谱中显示出强发射带。制备的纳米碳溶胶溶液的PL特性可归因于表面缺陷的陷阱态。
MF2 (M = Ca,Sr,Ba) nanocrystals (NCs) were synthesized via a solvothermal process in the presence of oleic acid and characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra, UV/vis absorption spectra, photoluminescence (PL) excitation and emission spectra, and lifetimes, respectively. In the synthetic process, oleic acid as a surfactant played a crucial role in confining the growth and solubility of the MF2 NCs. The as-prepared CaF2, SrF2 and BaF2 NCs present morphologies of truncated octahedron, cube and sheet in a narrow distribution, respectively. Possible growth mechanisms were proposed to explain these results. The as-prepared NCs are highly crystalline and can be well dispersed in cyclohexane to form stable and clear colloidal solutions, which demonstrate strong emission bands centred at 400 nm in photoluminescence (PL) spectra compared with the cyclohexane solvent. The PL properties of the colloidal solutions of the as-prepared NCs can be ascribed to the trap states of surface defects.