Synthesis of Nanocrystalline KTiOPO4 Powder by Chemical Method

Nanocrystalline potassium titanyl phosphate (KTiOPO₄, KTP) powder with average particle size of 25–50 nm has been synthesized from aqueous solution of titanyl chloride through coprecipitation method, using aqueous solution of potassium dihydrogen phosphate and potassium carbonate in the presence of triethanolamine (TEA) as a capping agent. In the presence of tetrapotassium pyrophosphate as a capping agent it produces the particles having average size around 70–80 nm. The same sample with average particle size ∼250 nm has also been synthesized without any capping agent. Initial amorphous phase after precipitation requires heat treatment at 500–550°C for 2 h to generate nanocrystalline powders of KTP. Formation of the KTP phase in the heat-treated samples has been confirmed through X-ray powder diffraction, thermogravimetric and differential thermal analysis, ³¹P Magic angle spinning-nuclear magnetic resonance and Fourier transform infrared spectroscopy studies, and surface area measurements.