Phase transformations upon the synthesis of Y3Al5O12:Nd

Methods of X-ray diffraction and thermal analysis have been used to study the processes of the formation of activated yttrium aluminum garnet Y3Al5O12:Nd (YAG:Nd) upon the thermal decomposition of carbonate precursors (two-phase nanocrystalline (Y,Nd)(OH)CO3 center dot nH(2)O-NH4Al(OH)(2)CO3 and an amorphous material) obtained by the coprecipitation from a solution of inorganic salts. It has been shown that the cubic structure of the garnet begins forming at a temperature of 900A degrees C and is developed from the hexagonal metastable yttrium aluminate YAlO3, which starts forming (as an intermediate phase) at 800A degrees C. The values of the lattice parameter a of the cubic structure and the X-ray density of the synthesized garnet Y2.97Nd0.03Al5O12 for the sample of the transparent phase-pure ceramics obtained are 1.2011 nm and 4.562 g/cm(3), respectively.