Synthesis and characterization of LnPO4 • nH2O (Ln = La, Ce, Gd, Tb, Dy) nanorods and nanowires

Aqueous precipitation method has been used to synthesize lanthanide orthophosphates LnPO(4) nH(2)O (Ln = La, Ce, Gd, Tb, Dy) with high purity and yield. It has been shown by XRD, TGA, and FTI R characterization that the as-synthesized samples are the LnPO, hydrates (LnPO(4) center dot nH(2)O) with hexagonal rhabdophane-type structure. The X-ray diffraction peaks and absorption of PO43- groups 4 show a systematic shift from LaPO4 center dot nH(2)O to DyPO4 center dot nH(2)O due to the effect of lanthanide ionic contraction. The value of n in LnPO(4) center dot nH(2)O depends on the lanthanide element and synthetic condition. Field-emission scanning electron microscopy observations show the morphology of as-synthesized samples, which consist entirely of nanorods/nanowires with diameters of 30-100 nm and lengths ranging from several hundreds of nanometers; to several micrometers. The anisotropic growth of crystals should be responsible for the formation of nanorods/nanowires, which is related to the hexagonal crystal structure.