Seminar Announcement: María Teresa Colomer Bas

Data pubblicazione: 6-dic-2015 13.37.09

Announcement

Friday, 04 December 2015, 15:00

Sala Grande Palazzina B via alla Cascata 56/C

"Effect of Tb³⁺ doping and Self-generated Pressure on the Crystallographic/Morphological Features and Thermal Stability of LaPO₄∙nH₂O Single-Crystal Nanorods"

María Teresa Colomer Bas

Instituto de Cerámica y Vidrio, CSIC, C/Kelsen 5, 28049 Madrid, Spain

Abstract

Tb³⁺-doped LaPO₄∙nH₂O single-crystal nanorods have been obtained by a simple and fast microwave-assisted hydrothermal synthesis. The effect of Tb³⁺-doping content (in the range 0‒20 mol.%) and autogeneous/self-generated pressure (in the range 2.3‒3.4±0.1 bar) on the crystallographic/morphological features and thermal stability of single-crystal nanorods of LaPO₄∙nH₂O was investigated. High-quality rhabdohane-type single-crystal nanords are obtained in all cases. However, their aspect ratio decreases with increasing self-generated pressure during the synthesis and with Tb³⁺ doping. In addition, it is shown that the Tb³⁺ solutes are incorporated into the LaPO₄∙nH₂O host, forming substitutional solid solutions with progressively smaller unit-cell volume but with identical thermal stability. It is also demonstrated that monazite-type single-crystal La_1-xTb_xPO₄ nanorods can be obtained by calcining their rhabdophane-type La_1-xTb_xPO₄∙nH₂O counterparts at ~700 ºC in air. The influence of the aspect ratio of the nanorods on the PL properties is now in progress.

Keywords: Tb³⁺, LaPO₄, hydrothermal synthesis-assisted by MWs, morphology, structure, photoluminescent properties.