Crystal Structures,Anisotropic Growth,and Optical Properties:Controlled Synthesis of Lanthanide Orthophosphate One-Dimensional Nanomaterials

摘要

The fundamental understanding of the relationship between crystal structure and the dynamic processes of anisotropic growth on the nanoscale,and exploration of the key factors governing the evolution of physical properties in functional nano-materials,have become two of the most urgent and challenging issues in the fabrication and exploitation of functional nanomaterials with designed properties and the development of nanoscale devices.Herein,we show how structural and kinetic factors govern the tendency for anisotropic growth of such materials under hydro-thermal conditions,and how the crystal structure and morphology influence the optical properties of Ln~(3+)-doped nano-crystals.The synthesis of phase-pure and single-crystalline monoclinic,hexagonal,and tetragonal one-dimensional LnPO_4 nanostructures of different aspect ratios by means of kinetically controlled hydrothermal growth processes is demonstrated.It is shown that the tendency for anisotropic growth under hydrothermal conditions can be enhanced simply by modifying the chemical potentials of species in the reaction solution through the use of carefully selected chelating ligands.A systematic study of the photolumines-cence of various Eu~(3+)-doped lantha-nide phosphates has revealed that the optical properties of these nanophos-phors are strongly dependent on their crystal structures and morphologies.