Morphology-controlled synthesis of gadolinium fluoride nanocrystalsvia ultrasonic and salt assisted method

Abstract

Gadolinium fluoride Na_xGd_yF_x+3y crystals with different morphologies and compositions have been successfully synthesized via a facile ultrasonic and salt assisted method at room temperature without any template or organic additive. Crystal structure and morphology of the fluorides were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Reaction conditions, such as ultrasonic irradiation, F/Gd molar ratio (R(F/Gd)), concentration of sodium nitrate and ultrasonic time have a close relationship with the morphology and phase composition of the final products. The growth mechanism of the uniform and monodisperse GdF₃ nanospindles was proposed based on the time-dependent experiments. The photoluminescent (PL) properties of the as-obtained products revealed that Eu³⁺ doped NaGdF₄ nanocrystals with different morphologies present characteristic luminescence of Eu³⁺, and their emission intensities strongly depend on morphology.