title: Solvothermal synthesis of well-dispersed MF(2) (M = Ca,Sr,Ba) nanocrystals and their optical properties.
abstract: MF(2) (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 MF(2) NCs. The as-prepared CaF(2), SrF(2) and BaF(2) 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.
authors.affiliation: State Key Laboratory of Application of Rare Earth Resources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China. Graduate University of the Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Zhang
authors.forename: Zewei
authors.initials: Z
authors.lastname: Quan
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Piaoping
authors.initials: P
authors.lastname: Yang
authors.forename: Hongzhou
authors.initials: H
authors.lastname: Lian
authors.forename: Jun
authors.initials: J
authors.lastname: Lin