Luminescence from ZrO₂ Nanopowders Doped with Sm³⁺ Ions Processed by Polyol Method at Low Processing Temperature

Abstract

ZrO2 and ZrO2:Sm3+ nanopowders are synthesized by means of polyol method, from [Zr(NO3)2.xH2O] and (SmCl3·6H2O) precursors dissolved in a diethylene glycol medium. X‐ray diffraction (XRD) results show polymorphic powders because monoclinic structure and tetragonal are exhibited. The crystal size is estimated by Scherrer formula; an averaged crystallite size of 9 nm is obtained. Surface morphology study, by means of SEM, evidences multiform particles, some with straight edges associated with monoclinic or tetragonal structure. The chemical composition microanalysis results indicate agreement with ideal stoichiometry for ZrO2 and ZrO2:Sm3+ powders. The photoluminescence emission spectra show that maximum intensity is reached at λ = 614 nm due to transition 4G5/2→6H7/2, exciting with λex = 240 nm, which corresponds to sample ZrO2:Sm3+ (0.75 at%); this sample is labeled as M3. Very similar results are obtained by cathodoluminescence studies. On the contrary, exciting with λex = 380 nm (monitoring emission band peaked at 614 nm), emission bands of host lattice and ZrO2:Sm3+ are favored simultaneously. The luminescent quenching phenomenon occurs when doping concentration (Sm3+ ions) is >=0.75 at%. The photoluminescent emission exhibits a reddish orange color, characteristic of Sm3+ ions, and yellowish‐orange for cathodoluminescence emission.