Optical properties of Eu and Er doped LaAlO3 nanopowders prepared by low-temperature method

LaAlO3 nanoparticles doped with Eu3+ and Er3+ ions were synthesized at 500 °C in a two-step process by combining a mechanically induced metathesis reaction and molten salt synthesis. The obtained samples were characterized by XRD and TEM methods, which showed that the mean crystallite size is ∼45 and ∼57 nm, respectively. Furthermore, excitation and luminescence spectra as well as decay profiles were measured for the synthesized samples. These studies suggested that the Eu3+ ions are located at three different local sites without inversion symmetry. Our studies also showed up-conversion emission in the samples doped with Er3+ ions. The up-conversion mechanism has been discussed.

The example up-conversion spectra of 1% and 2% Er3+-doped samples under 980 nm photoexcitation (a) and energy transfer scheme (b) in Er3+-doped LaAlO3 nanopowders. Figure optionsDownload as PowerPoint slideHighlights
► Er and Eu doped LaAlO3 samples were synthesized at remarkably low temperatures.
► The mean crystallite size of the obtained samples is 45–57 nm.
► Luminescence and excitation spectra as well as decay profiles were measured.
► Eu3+ ions are located at three different local sites without inversion symmetry.
► We discuss mechanism of the up-conversion mechanism in Er3+ doped samples.