Effect of annealing temperature in the emission properties of nanocrystalline CaZr0.9SmxDy0.1−xO3 systems prepared via self-propagating combustion synthesis

Abstract

This study investigates the photoluminescent properties of Samarium and Dysprosium co-doped nanocrystalline CaZrO3 perovskites that were prepared through self-propagating combustion synthesis. The prepared nanopowders were characterized using X-ray diffraction, Fourier Transform Infrared spectroscopy, Transmission Electron Microscopy, UV-Visible spectroscopy and photoluminescence spectroscopy. The orthorhombic (Pnma) perovskite structure of the prepared samples were confirmed using X-ray diffraction studies and the particle size of the samples were calculated to be in the range of 20-30 nm using transmission electron microscopic studies. The nanocrystalline Sm3+/Dy3+ doped CaZrO3 samples were annealed at 600°C, 800°C, 1000°C, 1200°C, 1250°C and 1400°C for 2 hours and the effect of annealing temperatures on the emission properties were also studied. Sm3+/Dy3+ co-doped CaZrO3 systems yield two different emissions at two different excitations when annealed at high temperatures. Emissions corresponding to the transition between 4F9/2 → 6H15/2 and 4F9/2 → 6H13/2 levels in Dy3+ ions were observed at 484 nm and 575 nm respectively while peaks corresponding to that of Sm3+ ions were observed at 567 nm, 602 and 650 nm due to the 4G5/2 → 6H5/2, 4G5/2 → 6H7/2 and 4G→65/2H11/2 transitions of Sm3+ ions. Chromaticity diagrams of the emission spectra of nanopowders, based on their luminescence studies were also investigated.