Molten chloride synthesis, structural characterisation and luminescence spectroscopy of nanocrystalline Eu3+ doped BaTiO3 and SrTiO3
| Autor: | Stefano Polizzi, F. Agnoli, Marco Bettinelli, Inas Kamal Battisha, Adolfo Speghini |
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| Rok vydání: | 2002 |
| Předmět: |
Photoluminescence
Materials science Mechanical Engineering Doping Mineralogy chemistry.chemical_element Condensed Matter Physics Tetragonal crystal system chemistry.chemical_compound Crystallography chemistry Mechanics of Materials Impurity X-ray crystallography Strontium titanate General Materials Science Luminescence Europium |
| Popis: | We report on the synthesis in molten NaCl, the morphological and structural characterisation and the luminescence spectroscopy of ultrafine BaTiO 3 and SrTiO 3 doped with Eu 3+ . The synthesis yields monophasic tetragonal BaTiO 3 :Eu 3+ and cubic SrTiO 3 :Eu 3+ . Crystals of SrTiO 3 have a cubic habit and size of about 200 nm, whereas BaTiO 3 is composed of micrometer-sized interpenetrated crystals with more rounded shapes. A large amount of lattice disorder is present inside the crystals, especially in the BaTiO 3 sample. The luminescence spectrum of ultrafine SrTiO 3 :Eu 3+ is dominated by the 5 D 0 → 7 F 2 transition, suggesting a strong distortion of the Eu 3+ sites. The disorder contributes, together with the presence of numerous charge compensation mechanisms, to the strong inhomogeneous broadening of the 5 D 0 → 7 F J luminescence bands of Eu 3+ . Ultrafine BaTiO 3 :Eu 3+ is nonluminescent, presumably due to the higher concentration of defects, compared to the SrTiO 3 host. |
| Databáze: | OpenAIRE |
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