Synthesis optimization, structural evolution and optical properties of Y0.9Er0.1Al3(BO3)4 nanopowders obtained by soft chemistry methods

This paper describes the structural evolution of Y0.9Er0.1Al3(BO3)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 Y0.9Er0.1Al3(BO3)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 4I13/2 and 4I15/2 levels were determined. Finally, for the first time the Raman spectrum of Y0.9Er0.1Al3(BO3)4 crystalline phase is also presented.

Graphical abstractPhase formation diagram of Y0.9Er0.1Al3(BO3)4 crystalline solid solution powders from the polymeric precursor method and the sol–gel method with heat treatments in oxygen-rich atmosphere at 5 °C/min. δ represents minor amount of the crystalline phase.Figure optionsDownload full-size imageDownload as PowerPoint slide