A novel solution method for selective synthesis of pure t-LaVO4

Tetragonal phase LaVO₄ (t-LaVO₄) was successfully selectively synthesized through a simple solution method with La(NO₃)₃ and NaVO₄ as starting materials without any templates or catalysts. The products were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). XRD patterns showed that pure t-LaVO₄ could be obtained in wide ranges of pH value and crystallization temperature. TEM images revealed that nanorods with different aspect ratios were obtained in different synthesis conditions. The shorter nanorods had mean diameters of about 18-25 nm and lengths of 40-60 nm. However, the longer nanorods had uniform sizes with an average aspect ratio about 10. It was interesting to discover that t-LaVO₄ could be formed even at room temperature (RT), which might be beneficial for a large scale production. Different luminescence performances of the samples doped 5% Eu³⁺ were also investigated.