Title :

Synthesis, structural and luminescence properties of (La1−xLnx)2Ti2O7 (Ln=lanthanides) solid solutions

Author(s) :

Bayart, Alexandre [Auteur]
Katelnikovas, Arturas [Auteur]
Blach, Jean-Francois [Auteur]
Rousseau, Jolanta [Auteur]
Unité de Catalyse et Chimie du Solide - UMR 8181 [UCCS]
Saitzek, Sebastien [Auteur]

Journal title :

Journal of Alloys and Compounds

Volume number :

683

Pages :

634-646

Publication date :

2016-10-25

HAL domain(s) :

Chimie/Catalyse
Chimie/Chimie inorganique

English abstract : [en]

The stability limit between the layered-perovskite/monoclinic and pyrochlore/cubic structures was investigated for the entire series of (La1−xLnx)2Ti2O7 with Ln = Pr to Lu prepared by solid-state reaction. Complete solid ...
Show more >The stability limit between the layered-perovskite/monoclinic and pyrochlore/cubic structures was investigated for the entire series of (La1−xLnx)2Ti2O7 with Ln = Pr to Lu prepared by solid-state reaction. Complete solid solutions were obtained for Ln = Pr or Nd. However, when the ionic radius of Ln3+ decreases (either, Sm3+ toward Lu3+), only partial solid solutions are achieved. The substitution rate decreases drastically when the ionic radius decreases. The energy bands gap were also determined using UV-visible diffuse reflectance spectroscopy. La2Ti2O7 acts as an excellent host matrix, in particular for the substitution of lanthanide ions, thus leading the creation of new emitting phosphors with a wide variety of colours. The luminescence properties of the (La1−xErx)2Ti2O7, (La1−xEux)2Ti2O7, (La1−xTbx)2Ti2O7 and (La1−xTmx)2Ti2O7 oxides have been especially described in this work. Among these compounds, (La0.6Eu0.4)2Ti2O7 presents the best quantum efficiency (42% under an excitation wavelength set at 393.5 nm) as well as good thermal stability which is suitable for use with near-UV LED chips. Finally, the CIE-1931 Chromaticity coordinates were also calculated for all phosphors.Show less >

Language :

Anglais

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

ENSCL
CNRS
Centrale Lille
Univ. Artois
Université de Lille

Collections :

• Unité de Catalyse et Chimie du Solide (UCCS) - UMR 8181

Research team(s) :

Catalyse et chimie supramoléculaire (CASU)
Couches minces & nanomatériaux (CMNM)

Submission date :

2019-09-25T14:04:34Z