Abstract
Ordered mesostructured LaF3 nanoarrays have been, for the first time, synthesized via a one-step nanocasting process using La(CF3COO)(3) as a precursor and mesoporous silica as a hard template. The characterization of SAXS and XRD, patterns and TEM and SEM images shows that the LaF3 nanowire arrays have long-range regularity of hexagonal mesostructure (p6mm) and single-crystalline feature. N-2-sorption isotherms reveal that ordered mesoporous LaF3 products have high BET specific surface area (similar to 75 m(2)/g), large pore volume (0.15 cm(3)/g), and narrow pore-size distribution (the mean value of 4.3 nm). The upconversion fluorescence has been realized in the Yb3+/Er3+ (red/green) and Yb3+/TM3+ (blue) codoped LaF3 nanoarrays by upconversion (UC) excitation in the near-infrared region. The UC emission population for F-4(9/2), H-2(11/2), S-4(3/2), and H-2(9/2) levels in the Yb3+/Er3+ codoped LaF3 nanowire array matrixes depends on Er3+ concentration, the excitation density, and the specific surface areas.