Nd(III) and Yb(III) ions incorporated in Y4Al2O9 obtained by sol‐gel method: synthesis, structure, crystals and luminescence

The nanocrystalline powders of Y4Al2O9 (YAM) pure and doped by Nd, Yb and codoped by Nd and Yb were obtained via modified sol-gel method. These powders were characterized by X-ray diffraction method, scanning electron microscopy and high resolution scanning electron microscopy, luminescence spectroscopy and differential thermal analysis (DTA). We obtained single phase powders of crystalline structure with average size 70 nm exhibiting interesting luminescent properties. Efficient non-radiative energy transfer between Nd and Yb was found. DTA confirmed the phase transition at about 1400 °C. From these nanocrystalline powders, the crystals YAM:Yb, YAM:Yb,Nd were grown by micro-pulling down technique. They were cracking during cooling owing to the phase transition. Luminescent properties of YAM:Nd,Yb crystals were identical with properties of corresponding nanopowders within experimental incertitude. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)