$LaYO_{3}:Sm^{3+}$ Nanocrystalline Phosphor: Preparation and Emission Properties

Samarium doped $LaYO_{3}$ nanocrystalline phosphor powders are obtained by polymer complex solution method. Stoichiometric quantities of $La_{2}O_{3},$ $Y_{2}O_{3}$ and for dopant ions $Sm_{2}O_{3}$ were dissolved in hot nitric acid. Polyethylene glycol was added in solutions in 1:1 mass ratio to corresponding metal nitrates to form gel. The gel is combusted and annealed at 800°C for two hours to form nanopowder samples. Crystalline structure and phase purity is checked by X-ray diffraction and show that this material is synthesized in cubic bixbyite type structure for the first time. Luminescence properties of $Sm^{3+}$ doped $LaYO_{3}$ exhibited characteristic orange-red emission coming from the intra-4f-shell $\text{}^{4}G_{5/2} \rightarrow \text{}^{6}H_{J}$ electron transitions with emission decay of 1.5 ms. Energy level positions are derived from emission and excitation spectra.