| Summary: | Red-emitted Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> nanophosphor coated on a mica flake (Y<sub>2</sub>O<sub>3</sub>:Eu@MF) or on TiO<sub>2</sub> having a rutile crystalline mica flake (Y<sub>2</sub>O<sub>3</sub>:Eu@TMF) has been prepared by an electrostatic interaction with the wet-coating method for the purpose of a pigment with luminescent and gloss properties. Aggregated Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup>, prepared by the template method, was dispersed into nanosol by a controlled bead-mill wet process. The (+) charged Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> nanosol was effectively coated on the (−) charged mica flake (MF) or the TiO<sub>2</sub>/mica flake (TMF) by an electrostatic interaction between the Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> nanoparticles and MF or TMF at pH 6–8. The coating factors of Y<sub>2</sub>O<sub>3</sub>:Eu@MF were also studied and optimized by controlling the pH, stirring temperature, calcination temperature, and coating amount of Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup>. The Y<sub>2</sub>O<sub>3</sub>:Eu<sup>3+</sup> was partially coated and optimized on the MF or TMF surface with a coating coverage of about 40–50% or 60–70%, respectively. Y<sub>2</sub>O<sub>3</sub>:Eu@MF and Y<sub>2</sub>O<sub>3</sub>:Eu@TMF were exhibiting the luminescent property of a red color under a 254 nm wavelength, and had a color purity of over 95% according to CIE chromaticity coordinates. These materials were characterized by X-ray diffraction, FE-SEM, zeta potential, and a fluorescence spectrometer. These materials with luminescent and gloss properties prepared in this work potentially meet their applications for security purposes.
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