A solution-phase route for the preparation of single-crystalline iron phosphide nanorods and nanowires is reported. We have shown that the mixture of trioctylphosphine oxide (TOPO) and trioctylphosphine (TOP), which are commonly used as the solvents for semiconductor nanocrystal synthesis, is not entirely inert. In the current process, TOP, serving as phosphor source, reacts with Fe precursors to form FeP nanostructures with large aspect ratios. In addition, the experimental results show that both TOP and TOPO are necessary for the formation of FeP nanowires and their ratio appears to control the morphology of the produced FeP structures. A possible growth mechanism is discussed.

β-NaGdF(4) : Yb(3+)/Er(3+) nanoparticles (NPs) codoped with Li(+) ions were prepared for the first time via a thermal decomposition reaction of trifluoroacetates in oleylamine. The influence of site occupancy of Li(+) on the upconversion emission of β-NaGdF(4) : Yb(3+)/Er(3+) NPs was investigated in detail. The upconversion emission intensity was significantly enhanced by introducing different concentrations of Li(+) ions. In contrast to lithium-free β-NaGdF(4) : Yb(3+)/Er(3+), the green and red UC emission intensities of the NPs codoped with 7 mol% Li(+) ions were enhanced by about 47 and 23 times, respectively. The luminescence enhancement should be attributed to the distortion of the local asymmetry around Er(3+) ions. The mechanisms for the enhancement of upconversion emission were discussed. In addition, it was found in our research work that β-NaGdF(4) : Yb(3+)/Er(3+) NPs exhibited paramagnetic features at room temperature and the magnetization was slightly increased by introducing Li(+) ions.