The effect of precipitant concentration on the formation procedure of yttrium aluminum garnet (YAG) phase

In this paper, the effect of precipitant concentration on the formation procedure of YAG phase, which is actually a solid reaction controlled by the diffusion of aluminum ions into the yttria particles, is investigated. Under higher precipitant concentration, the size of yttria particles formed is in micron level and alumina particle is in the form of clusters of small particles. Therefore the element diffusion distance is lengthened and higher temperature (≥1350 °C) is essential for the completion of phase transitions. Under lower precipitant concentration, the sizes of yttria particles and alumina particles are both smaller than 100 nm and two kinds of oxides are mixed uniformly, so the phase transition procedure can complete at lower temperatures (≤1200 °C).