Hydrothermal synthesis of lutetium disilicate nanoparticles

A simple, low-cost hydrothermal method was developed to synthesize irregular-and rod-shaped lutetium disilicate (Lu2Si2O7) powders with sizes ranging from 71 to 340 nm. The synthesis temperature was 260 degrees C, which is nearly 1300 degrees C lower than that required for the solid-state reaction. The results indicated that both the hydrothermal temperature and pH values had great influences on the composition, crystalline phase and morphology of the powders. The formation mechanism, basic thermophysical properties, stability and anticorrosion properties of the Lu2Si2O7 powders were also investigated. The obtained powders possessed low thermal conductivity, a suitable thermal expansion coefficient (3.92-5.17 x 10(-6) K-1) with the silicon-based substrate and excellent thermal and structural stability. During hot corrosion testing, the surfaces of the samples appeared to react with the water and molten salt vapors, but no serious failure occurred. (C) 2012 Elsevier Inc. All rights reserved.