Synthesis and sintering of submicron Nd:YAG particles prepared from carbonate precursors

Abstract

Using high-temperature X-ray diffraction, differential scanning calorimetry, and electron microscopy, we have studied the formation of yttrium aluminates and Nd:YAG (YAG) activated garnet nanoparticles during the thermal decomposition of a poorly crystallized carbonate precursor prepared in the NH₄Al(OH)₂CO₃–(Y,Nd)(ОН)CO₃ nanosystem and the development of the morphological structure of powders during heating to a temperature of 1350°C. The results demonstrate that heat treatment in the temperature range 850–950°C leads to the formation of metastable nonstoichiometric YAlO₃ with a garnet-like structure, which reacts with Al₂O₃ at a temperature of 1000°C to form YAG. The cubic cell parameter a and X-ray density of YAG crystals with the composition Y_2.97Nd_0.03Al₅O₁₂ synthesized at 1200°C are 1.2009 nm and 4.565 g/cm³, respectively, and the average particle size is 108 nm. Using carbonate route, we prepared transparent Nd:YAG ceramics with a relative density of 99.7%, X-ray density of 4.562 g/cm³, and crystallite size in the range 1–7 μm.