X-ray powder diffraction characterization of residual stresses and strains in Y3Al5O12:Nd3+ nanocerarnics

Y3Al5O12:Nd3+ nanoceramics were obtained by sintering nanocrystalline Y3Al5O12:Nd3+ powders at 450 degrees C under different pressures between 2 and 8 GPa. The structural purity, residual stress, strain, texture, and crystallite size of the products were analysed with X-ray powder diffraction. The results indicate that the average crystallite size remains unchanged at about 30 nm in spite of the heating and the pressure applied. No texture was observed. On the other hand, the microstrains increase with increasing pressure, while the residual stresses are at their maximum in the green body and the sample processed at 8 GPa. Increasing strains were observed to increase the width of the luminescence lines and to decrease the luminescence decay times.