title: Original Synthetic Route To Obtain a SrAl2O4 Phosphor by the Molten Salt Method: Insights into the Reaction Mechanism and Enhancement of the Persistent Luminescence.
abstract: SrAl2O4:Eu(2+), Dy(3+) has been extensively studied for industrial applications in the luminescent materials field, because of its excellent persistent luminescence properties and chemical stability. Traditionally, this strontium aluminate material is synthesized in bulk form and/or fine powder by the classic solid-state method. Here, we report an original synthetic route, a molten salt assisted process, to obtain highly crystalline SrAl2O4 powder with nanometer-scale crystals. The main advantages of salt addition are the increase of the reaction rate and the significant reduction of the synthesis temperature because of much higher mobility of reactants in the liquid medium than in the solid-state method. In particular, the formation mechanism of SrAl2O4, the role of the salt, and the phase's evolution have been explored as a function of temperature and time. Phosphorescent powders based on SrAl2O4:Eu(2+), Dy(3+) with high crystallinity are obtained after 1 h treatment at 900 °C. This work could promote further interest in adopting the molten salt strategy to process high-crystallinity materials with enhanced luminescence to design technologically relevant phosphors.
authors.affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC , Kelsen 5, 28049, Madrid, Spain.
authors.forename: Rocío Estefanía
authors.initials: RE
authors.lastname: Rojas-Hernandez
authors.affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC , Kelsen 5, 28049, Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Rubio-Marcos
authors.affiliation: Departments of Chemistry and Materials Engineering, Federal University of Sao Carlos , 13565-905 Sao Carlos, SP, Brazil.
authors.forename: Ricardo Henrique
authors.initials: RH
authors.lastname: Gonçalves
authors.affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC , Kelsen 5, 28049, Madrid, Spain.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Rodriguez
authors.affiliation: CNRS, CEMHTI UPR3079, University of Orléans , F-45071 Orléans, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Véron
authors.affiliation: CNRS, CEMHTI UPR3079, University of Orléans , F-45071 Orléans, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Allix
authors.affiliation: CNRS, CEMHTI UPR3079, University of Orléans , F-45071 Orléans, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Bessada
authors.affiliation: Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC , Kelsen 5, 28049, Madrid, Spain.
authors.forename: José Francisco
authors.initials: JF
authors.lastname: Fernandez