Eu 3+ addition effect on the stability and crystallinity of fiber single crystal and nano-structured Y 2O 3 oxide

Abstract

Nano-structured powders and fiber single crystals of cubic yttrium oxide undoped and Eu 2O 3 doped with luminescent properties were prepared using two techniques. The first one is focused on direct oxide precipitation at low temperature in which europium-doped yttrium oxide (Y 2O 3:Eu 3+) particles sizes less than 5 nm were synthesized in colloidal solution, followed by a controlled precipitation to obtain fine sub-micrometric powders. The second method is based on fiber single crystal growth using laser-heated pedestal growth (LHPG) and CO 2 laser beam as heating source at 10.6 μm and homogeneous starting rod materials obtained from the synthesis of nano-scale materials. The fibers grown by LHPG technique were single crystal, transparent, homogeneous, red color when Eu 3+ concentration is high. The crystal fiber quality decreases with increasing Eu 3+ concentration higher than 2% because of segregation problem. The materials obtained by the soft chemistry are cubic and lies in the nano-meter range. The purity of the materials, europium concentration limit, particles sizes and structure were obtained from X-ray powders diffraction at room temperature. The segregation coefficient of Eu 3+ is measured from EPMA analysis. The morphology of the materials was obtained using SEM. The luminescence of Eu 3+ has been detected by excitation at λ = 254 nm .