Synthesis optimization, structural evolution and optical properties of Y 0.9Er 0.1Al 3(BO 3) 4 nanopowders obtained by soft chemistry methods

Abstract

This paper describes the structural evolution of Y 0.9Er 0.1Al 3(BO 3) 4 nanopowders using two soft chemistry routes, the sol–gel and the polymeric precursor methods. Differential scanning calorimetry, differential thermal analyses, thermogravimetric analyses, X-ray diffraction, Fourier-transform infrared, and Raman spectroscopy techniques have been used to study the chemical reactions between 700 and 1200 °C temperature range. From both methods the Y 0.9Er 0.1Al 3(BO 3) 4 (Er:YAB) solid solution was obtained almost pure when the powdered samples were heat treated at 1150 °C. Based on the results, a schematic phase formation diagram of Er:YAB crystalline solid solution was proposed for powders from each method. The Er:YAB solid solution could be optimized by adding a small amount of boron oxide in excess to the Er:YAB nominal composition. The nanoparticles are obtained around 210 nm. Photoluminescence emission spectrum of the Er:YAB nanocrystalline powders was measured on the infrared region and the Stark components of the 4 I 13/2 and 4 I 15/2 levels were determined. Finally, for the first time the Raman spectrum of Y 0.9Er 0.1Al 3(BO 3) 4 crystalline phase is also presented.