Formation of BaMgAl₁₀O₁₇:Eu phosphor particles with spherical shape and filled morphology in the flame spray pyrolysis

Fine-sized, spherical BaMgAl₁₀O₁₇:Eu²⁺ phosphor particles with filled morphologies were prepared by flame spray pyrolysis. Precursor particles prepared by flame spray pyrolysis at a low-temperature diffusion flame and a short particle residence time within the diffusion flame were of large size and had hollow structures. On the other hand, precursor particles prepared at optimum preparation conditions were fine sized, had filled structures, and narrow size distributions. The melting of large-sized intermediate particles with hollow structures within the high-temperature diffusion flame formed fine-sized, spherical precursor particles with filled structures. The BaMgAl₁₀O₁₇:Eu ²⁺ phosphor particles prepared by flame spray pyrolysis at optimum preparation conditions were fine-sized and had regular morphologies after post-treatment at 1400°C. The mean size of the BaMgAl₁₀O ₁₇: Eu²⁺ phosphor particles was 1.0μm. The photoluminescence intensity of fine-sized, spherical BaMgAl₁₀O ₁₇: Eu²⁺ phosphor particles with filled structures was higher than that of large-sized phosphor particles with hollow structures excited by the vacuum ultraviolet light at the wavelength, 147 nm.