Synthesis And Characterization Of Rare Earth Ions-doped Lanthanum Oxybromide Low-dimensional Nanomaterials

LaOBr with low phonon energies are excellent luminescent host materials, and they can exhibit efficient luminescence via doping with different rare earth activators. Rare earth doped LaOBr materials have been used in X-ray radiation image intensifying screen, storage system and biomedical. Presently, LaOBr nanomaterials with different morphologies have been synthesized, including nanoparticles, nanorods and feather-shaped particles. Various methods to prepare the above LaOBr have been reported including sol-gel method, direct solid-state reaction at high temperature, mechanochemical synthesis, and thermal decomposition method. However, one-dimensional nanomaterials have more novel properties than nanoparticles. In order to study their properties of one-dimensional nanomaterials, a simply method of preparing LaOBr nanomaterials must be explored. Electro spinning technology has been extensively explored as a simple and versatile method for forming inorganic nanomaterials. Hence, it is an important and meaningful subject of study to fabricate rare earth cations-doped LaOBr one-dimensional nanomaterials and to investigate their luminescence property.In this dissertation, LaOBr:RE~3+(RE=Tb, Er) nanofibers and nanobelts were fabricated via electrospinning technique combined with double-crucible method. In this process of preparation, rare earth oxide nanofibers and nanobelts were obtained by calcining composite fibers and belts at high temperature. Then LaOBr:RE~3+(RE=Tb, Er) nanofibers and nanobelts were prepared using double-crucible method via calcining rare earth oxide nanofibers and nanobelts. On the basis of above results, subsequent experiments had been modified. The bromine source as a component of precursor solution was dissolved in the precursor spinning solution. LaOBr:RE~3+(RE=Tb, Eu, Nd, Eu, Yb/Er) nanofibers and nanobelts were fabricated by calcining composite fibers and belts in air. LaOBr:RE3+(RE=Tb, Eu) hollow nanofibers were obtained by tuning the amount and the molecular weight of PVPThe samples were characterized by X-ray diffractometry (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and fluorescence spectroscope. The results showed that the LaOBr:RE~3+nanomaterials were the tetragonal phase in structure. The diameter of nanofibers was90-200nm, the width of nanobelts was1.5-6.0μm,and the thickness was100-200nm. The luminescence properties of LaOBr:RE~3+nanomaterials with various morphologies were also studied. These new findings lay the solid foundations for the luminescent properties of rare earth oxybromide low-dimensional nanomaterials.