title: Effect of thermal annealing on the kinetics of rehydroxylation of Eu3+:La2O3 nanocrystals.
abstract: Europium-doped lanthanum oxide (5 mol % Eu(3+):La(2)O(3)) was prepared by calcining europium-doped lanthanum hydroxide (5 mol % Eu(3+):La(OH)(3)) previously synthesized by a simple hydrothermal method. Interestingly, we observed different emission Eu(3+) 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 Eu(3+):La(OH)(3) depending on temperature and to study the evolution of La(2)O(3) 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 Eu(3+):La(2)O(3) sample.
authors.affiliation: Física i Cristal·lografia de Materials (FiCMa-FiCNA) and EMaS, Universitat Rovira i Virgili (URV), Campus Sescelades, Marcel·lí Domingo, s/n, E-43007 Tarragona, Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Méndez
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Cesteros
authors.forename: Lluís Francesc
authors.initials: LF
authors.lastname: Marsal
authors.forename: Alexandre
authors.initials: A
authors.lastname: Giguère
authors.forename: Dominique
authors.initials: D
authors.lastname: Drouin
authors.forename: Pilar
authors.initials: P
authors.lastname: Salagre
authors.forename: Pilar
authors.initials: P
authors.lastname: Formentín
authors.forename: Josep
authors.initials: J
authors.lastname: Pallarès
authors.forename: Magdalena
authors.initials: M
authors.lastname: Aguiló
authors.forename: Francesc
authors.initials: F
authors.lastname: Díaz
authors.forename: Joan Josep
authors.initials: JJ
authors.lastname: Carvajal