A novel samarium(III) polymer, [Sm2(C6H5COO)6(CH3OH)3]·CH3OH (1) has been synthesized and characterized by single crystal X-ray diffraction and magnetic measurements. Polymer 1 crystallizes in monoclinic space group P2(1)/c, with a = 15.1247(6), b = 18.3351(7), c = 21.1266(6) Å, β = 126.830(2)°, V = 4689.4(3) Å3, and Z = 4. Single crystal X-ray analysis reveals a chain-like structure of 1 consisted of alternating eight- and nine-coordinate Sm(III) ions bridged by benzoate ligands in different coordination modes. A treatment of the variable-temperature magnetic susceptibility using an expression deduced from free-ion approximation and molecular field theory suggests the existence of a weak antiferromagnetic coupling between the samarium ions.

The size controllable Gd2O3:Eu3+ luminescence nanotubes were successfully prepared using a simple method by coating gadolinium compounds on the carbon nanotubes and then firing the carbon nanotubes. The morphology of the obtained Gd2O3:Eu3+ nanotubes was determined by transmission electron microscopy (TEM). It was found that the obtained nanotubes have the outer diameters of ∼100 nm, the inner diameters of ∼50 nm, and the lengths of several tens of microns. The sizes of Gd2O3:Eu3+ nanotubes can be easily controlled by changing the reaction times and the concentration of reactants. X-ray diffraction (XRD) patterns showed that the Gd2O3:Eu3+ nanotubes begin to crystallize when annealing at the temperature of 600 °C, and the crystallinity increases with the increasing of the annealing temperature. The photoluminescence studies indicated that a strong emission peak at 610 nm is a characteristic red emission of Eu3+, and the emission intensity increases with the reaction times and concentration of reactants but decreases with the increasing of annealing temperature, which is probably because the residual carbon impurities on the surface of Gd2O3:Eu3+ nanotubes decrease the luminescence intensity of Gd2O3:Eu3+.

Spherical and submicrometer-sized hollow Gd2O3:Eu3+ phosphors were prepared by homogeneous precipitation and hydrothermal method by varying the concentrations of reactants and changing the synthesis conditions. In the precipitation step, the spherical nucleus was formed and grew to large particles. In the hydrothermal step, the large particles crystallized to solid or hollow spheres. At last, Gd2O3:Eu3+ phosphors were obtained by annealing at the temperature more than 600 °C. The deduced mechanics of forming the solid and hollow spheres was proposed. And the obtained spherical Gd2O3:Eu3+ phosphors had better red luminescence properties. The relative luminescence intensity and the lifetime increased with increasing annealing temperatures.

Crystalline Y2O3:Eu is of paramount significance in rare earth materials and research on luminescence spectra. In this work, the nanocrystalline Y2O3:Eu was coated with silica by a facile solid state reaction method at room temperature. The transmission electron microscope (TEM) photographs showed that the prepared Y2O3:Eu particle is polycrystalline with the size of 20 nm, the size of silica-coated particle is about 25 nm. The XPS spectra indicated that the silica layer is likely to interact with Y2O3:Eu by a Si–O–Y chemical bond. The luminescence spectra showed that the intensity of ground samples is lower than that of unground ones, the intensity of silica-coated phosphors is higher than that of the ground samples, while almost the same as that of the unground ones. Therefore, the silica coating decreases the surface defects of nanoparticles of the nanocrystalline Y2O3:Eu, thus increasing their luminescent intensity.