Low-temperature synthesis, luminescence and phonon properties of Er and/or Dy doped LaAlO3 nanopowders

Optical properties of Eu and Er doped LaAlO3 nanopowders prepared by low-temperature method

“…However, the methods applied for synthesis of aluminum-containing perovskites are in general time-consuming and challenging since they demand the optimization of many different experimental parameters such as pH, nature of starting materials, temperature and mixing procedures. Very recently, we have reported synthesis of LaAlO 3 , La 0.9 Dy 0.1 AlO 3 , La 0.9 Er 0.1 AlO 3 and La 0.8 Dy 0.1 Er 0.1 AlO 3 nanopowders by a novel ''green chemistry'' approach using alkali metal nitrates as low-temperature fluxes [25,26]. This method allowed obtaining pure and doped perovskite-type LaAlO 3 powders with very fine crystallite size (32-60 nm) at remarkably low temperatures, i.e.…”

“…This method allowed obtaining pure and doped perovskite-type LaAlO 3 powders with very fine crystallite size (32-60 nm) at remarkably low temperatures, i.e. already at 350 1C although firing at 500 1C was needed to get pure phases of La 0.9 Dy 0.1 AlO 3 , La 0.9 Er 0.1 AlO 3 and La 0.8 Dy 0.1 Er 0.1 AlO 3 [25,26]. X-ray diffraction, Raman scattering and infrared absorption revealed that the LaAlO 3 nanocrystallites have R3 c structure, the same as bulk LaAlO 3 [26].…”

“…already at 350 1C although firing at 500 1C was needed to get pure phases of La 0.9 Dy 0.1 AlO 3 , La 0.9 Er 0.1 AlO 3 and La 0.8 Dy 0.1 Er 0.1 AlO 3 [25,26]. X-ray diffraction, Raman scattering and infrared absorption revealed that the LaAlO 3 nanocrystallites have R3 c structure, the same as bulk LaAlO 3 [26]. However, IR spectroscopy revealed significant differences between these nanocrystalline samples and bulk LaAlO 3 , which were attributed to surface effects and polar nature of the observed modes [26].…”

Molten salts synthesis and electrical properties of Sr- and/or Mg-doped perovskite-type LaAlO3 powders

“…Alkali metal nitrates are preferred reaction media because of their low cost, low melting points (e.g., NaNO 3 = 303°C), high stability over a wide liquid temperature window (*550°C), and high water solubility which facilitates recovery of the target phase by a simple washing step [21]. As recently shown in different studies published by some of the present author group, both a metathesis reaction and molten salts synthesis might be combined to allow the preparation of pure and Er-and/or Dy-doped lanthanum aluminate nanoparticles at temperatures much lower than those previously reported in the literature using Li, Na, or K nitrates as fluxes [22,23]. In this article, we will give additional details on the reaction mechanism in sodium nitrate and show that with small changes, the method might be also further extended for preparing acceptor-doped, and thus oxygen-ion-conducting, LaAlO 3 materials.…”

“…Pristine and doped LaAlO 3 powders were prepared by a twosteps method consisting of a mechanically induced metathesis reaction followed by short firing at temperatures above sodium nitrate's melting point as previously described [22,23]. Analytical grade metal nitrates (Al(NO 3 …”