On the solubility of Nd3+ in Y3Al5O12
  Neodymium doped yttrium aluminum garnet powders (Nd:YAG or (Y{1-x}Nd{x})3Al5O12, x=0.15, 0.25, or 0.30, respectively) were prepared by a sol-gel technique. By DTA measurements up to 2000 deg C eutectic and liquidus temperatures could be determined. Exothermal peaks in the second and subsequent DTA heating runs indicate that the crystallized DTA samples are not in equilibrium. The section Y3Al5O12-Nd3Al5O12 of the concentration triangle Al2O3-Nd2O3-Y2O3 is proposed on the basis of thermodynamic calculations that allows to explain the experimental results by the balance of metastable phase states in the previously crystallized DTA samples. 
D. Klimm, S. Ganschow, A. Pajaczkowska, L. Lipinska