Luminescent SrSn(OH)6 nano-rods

The alkaline earth tin hydroxides having general formula MSn(OH)6 are the precursor materials for preparation of perovskite type MSnO3 nanomaterials, which are potential candidates for doping lanthanide ions like Nd3+, Er3+, Ho3+ etc for developing up conversion devices and NIR lasers. Bright luminescent SrSn(OH)6 nano-rods were prepared at room temperature by mixing aqueous solutions of strontium chloride and sodium stannate under vigorous stirring. SEM studies carried out on the samples confirmed the formation of nano-rods having length around 2-2.5μm and width less than 100 nm. As prepared SrSn(OH)6 nano-rods were doped with different amounts of lanthanide ions like Eu3+, Tb3+ and Dy3+ ions and their luminescence properties have been investigated. On excitation at 270 nm, bright bluish green emission has been observed from un-doped SrSn(OH)6 nano-rods. Broad emission from the nano-rods have been attributed to the radiative recombination of self trapped excitons with a lifetime of around 350 ps. Based on the luminescence studies it is inferred that up to 1.5 at % Eu3+ ions, it get incorporated at Sr2+ site in the SrSn(OH)6 lattice and beyond which it forms a separate europium containing phase. There exists strong energy transfer from host to lanthanide ions in these samples. On heating the as prepared SrSn(OH)6 nano-rods above 700 deg C leads to the formation of SrSnO3 phase and the morphology is maintained during the transformation process. (author)