Conditions and optical absorbency of SmBO₃ powder synthesized by sol-gel combustion method

The influential factors of precursor for preparation of SmBO₃ powder by sol-gel combustion method were investigated. The effects of calcination temperature and time on optical absorbency of SmBO₂ powder were examined. The results showed that when heating temperature was 80°C, molar ratio of H₂o to the sum of Sm and B 30, pH 2 and molar ratio of citric acid to the sum of Sm and B 1:1, the gel combusted steadily at 180°C, and then changed into white fluffy precursor. SmBO₂ powder was obtained when the precursor calcined at 750°C for 2 h, with an average particle size of 100 nm. There was strong absorption in 1.05-1.15 μm wavelength range, and the reflectivity of SmBO₃ powder reached a minimum value of about 0.41% at 1.07 μm wavelength. It was about 0.6% at 1.06 μm.