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 °C, which is nearly 1300 °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 (3.92–5.17×10−6 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.

An image for the as-prepared Lu2Si2O7 powders (left) and XRD pattern (right) (inset shows the SEM graph of powders).Figure optionsDownload as PowerPoint slideHighlights
► We synthesized Lu2Si2O7 powders via a hydrothermal process at 260 °C.
► Crystalline phase and morphology of the powders changed with experimental parameter.
► Hot corrosion was determined in an airflow environment containing alkaline vapor.