Study On The Properties Of Samarium And Terbium Doped Zirconia Nanomaterials

In the thesis,the zirconium alloys doped with Sm and Tb were prepared by a powder metallurgical method,then the Sm³⁺-doped ZrO₂ nanotube arrays and Tb³⁺-doped ZrO₂ nanotube arrays were prepared by anodizing corresponding alloys in?NH₄?₂SO₄ inorganic electrolyte and formamide+glycerol?denoted by FA+GE?organic electrolyte containing F^-,respectively.Morphologies,structures,elemental valence state,UV-vis diffuse reflectance spectra and photoluminescence properties were characterized by a scanning electron microscope?SEM?,an X-ray diffractometer?XRD?,an X-ray photoelectron spectroscope?XPS?,a UV-vis spectrophotometer?UV-Vis?and a fluorescence spectrophotometer?FL?,respectively.The evolution of crystal structure of the samples as functions of preparation condition and annealing temperature and their effects on the PL properties of the samples were investigated.1.The Sm³⁺-doped ZrO₂ nanotube arrays and Tb³⁺-doped ZrO₂ nanotube arrays were obtained in two kinds of preparation conditions?Condition?:0.5 M?NH₄?₂SO₄+0.25 wt%NH₄F+H₂O,20°C,40 V,3 h;Condition?:FA+GE?volume ratio 1:1?+1 wt%H₂O+1 wt%NH₄F,20°C,50 V,3 h?.Then the morphologies,structures and properties of the nanotube arrays obtained in these two conditions were characterized and studied.2.The studies of Sm³⁺-doped ZrO₂ nanotube arrays show that the samples obtained in inorganic electrolyte were mainly tetragonal phase;the samples annealed at below 400 ^oC obtained in organic electrolyte were mainly amorphous phase,and the samples annealed at above 400^oC which were crystallized were mainly monoclinic phase.The tetragonal ZrO₂ in the nanotubes was revealed to be beneficial for the improvement of the luminous efficiency.Under an excitation wavelength of 407 nm,the emission spectra consisted of two broad emission bands extending from 560 nm to580 nm and 600 nm to 630 nm with the greatest emission peak at 571 nm.3.The studies of Tb³⁺-doped ZrO₂ nanotube arrays show that the morphologies and crystal structures of the samples were similar to those of Sm³⁺-doped ZrO₂nanotube arrays.The tetragonal ZrO₂ in the nanotubes was revealed to be beneficial for the improvement of the luminous efficiency.Under the excitation wavelength of263 nm,there are four main emission peaks located at 489 nm,544 nm,584 nm and622 nm,respectively,and the strongest emission peak was located at 544 nm which is responsible for the characteristic green light emission.4.The Sm³⁺-doped ZrO₂ nanotube arrays,thin films,powders and Tb³⁺-doped ZrO₂ nanotube arrays,thin films,powders were compared in morphology,crystal structure,fluorescence properties and so on,and the comparison results show that Sm³⁺-doped ZrO₂ nanotube arrays and Tb³⁺-doped ZrO₂ nanotube arrays prepared by an anodization method exhibited different fluorescent properties from the corresponding thin films and powders,respectively.