Novel and Incredibly Facile Low Temperature Solid State Route to Nano-Sized Eu³⁺ Activated BaTiO₃ Phosphors

Barium titanate (BaTiO₃) has widespread applications in various fields of electronics due to its peculiar crystal structure and specific characteristics. For example, BaTiO₃ has interesting luminescence characteristics with wavelengths in red regions after introduction of Eu³⁺. Generically BaTiO₃:Eu³⁺ is synthesized through a hightemperature solid-state reaction that usually results in larger grain sized products. Although various alternative routes have been developed to obtain nano-sized products, they have limitations such as lower yield and needing special equipment and chemicals as well as post heat treatments. On the other hand, water assisted solid state reaction (WASSR) is a low temperature, environmentally friendly, and inexpensive process developed recently. Here, we report a novel WASSR route to synthesize nano-sized Eu³⁺ activated BaTiO₃ at 80 °C from readily available raw materials. X-ray diffraction patterns of synthesized phosphor confirmed the formation of cubic phase BaTiO₃. STEM EDS mapping of the as-synthesized sample showed an even distribution of host lattice elements as well as activator ion. The synthesized phosphor particles exhibited a size of 10–30 nm with PL and PLE characteristics well matching previous reports. In addition, nano-sized Ba_(1–x)TiO₃:xEu³⁺ (where x = 0.005, 0.01, 0.05, and 0.1) phosphors were synthesized through this novel and incredibly facile WASSR process at a low temperature of 80 °C.