Effect of Thermal Annealing on the Kinetics of Rehydroxylation of Eu3+:La2O3 Nanocrystals

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• 作者：Maria M茅ndez ; Yolanda Cesteros ; Llu铆s Francesc Marsal ; Alexandre Gigu猫re ; Dominique Drouin ; Pilar Salagre ; Pilar Formentı ; &#769 ; n ; Josep Pallar猫s ; Magdalena Aguil贸 ; Francesc Dı ; &#769 ; az ; Joan Josep Carvajal
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：June 4, 2012
• 年：2012
• 卷：51
• 期：11
• 页码：6139-6146
• 全文大小：596K
• 年卷期：v.51,no.11(June 4, 2012)
• ISSN：1520-510X

文摘

Europium-doped lanthanum oxide (5 mol % Eu³⁺:La₂O₃) was prepared by calcining europium-doped lanthanum hydroxide (5 mol % Eu³⁺:La(OH)₃) previously synthesized by a simple hydrothermal method. Interestingly, we observed different emission Eu³⁺ signatures depending on the phase of the host (lanthanum oxide or hydroxide) by cathodoluminescence. Taking into account that lanthanum oxide easily rehydroxylates in air, for the first time, we report the use of cathodoluminiscence as a novel characterization technique to follow the lanthanum oxide rehydroxylation reaction versus time according to different annealing procedures. Additionally, differential thermal-thermogravimetric analysis, infrared spectroscopy, and X-ray diffraction techniques were used to identify the phases formed from the Eu³⁺:La(OH)₃ depending on temperature and to study the evolution of La₂O₃ to La(OH)₃ versus time. The results showed that the higher the temperature and the longer the annealing time, the higher the resistance to rehydroxylation of the Eu³⁺:La₂O₃ sample.