Rapid solution combustion synthesis of sponge like mesoporous Ce3+ doped yttrium aluminium oxide

Abstract

We present here an effective and facile method to synthesize hierarchical sponge-like mesoporous trivalent cerium (Ce3+) doped cubic (YAG (Y3A5O12)) and monoclinic (YAM (Y4A2O9)) yttrium aluminium oxide (YAlO) by a single step self propagating low temperature combustion technique without any post heating. The X-ray diffraction study revealed the formation of YAG and YAM structures and optimum incorporation of dopant is confirmed through precipitated secondary phase at higher Ce3+ concentration. Raman spectra of undoped and Ce3+ doped YAlO shows the characteristics peaks of YAG and YAM structure. The field emission scanning electron micro graphs (FESEM) reveal highly porous sponge-like surface with individual pore size of about 12–15 nm. The photoluminescence studies show efficient single band emission spectra centered at 568 and 550 nm for Ce3+ doped YAG and YAM respectively due to intra-shell transitions of the rare earth atom, compared to negligible emission in visible region for undoped YAlO due to defects present in the host lattice. Influence of dopant and the changes observed in structural, morphological and luminescence studies due to differences in crystal field environment (cubic and monoclinic) are explained in detail. Such highly stable mesoporous material with luminescence in visible region is suited for applications in illumination devices like white LEDs for indoor and outdoor lighting and also high end biomedical applications such as tumor targeting.