LAUSR

Abstract This paper presents a study of the synthesis and structural properties of the pyrochlore-type titanates (Gd 1− x Eu x ) 2 Ti 2 O 7 . Six compositions with 0 ≤  x  ≤ 1 were prepared by solid-state reaction with thermal treatments at 1000 and 1200 °C under atmospheric pressure conditions. All the products were systematically characterized by X-ray powder diffraction (XRD), Raman spectroscopy, photoluminescence (PL) and photoluminescent excitation spectra (PLE). Structural refinements of X-ray powder diffraction data using Rietveld method show that all compounds of the (Gd 1− x Eu x ) 2 Ti 2 O 7 solid solution crystallize in a pyrochlore structure. The lattice parameters increase linearly with increasing Eu content in agreement with Vegard's rule. PL spectra show that the characteristic peaks correspond to the f–f transition 5 D 0 – 7 F J ( J  = 1, 2, 3 and 4) of Eu 3+ . The effect of Eu 3+ ions concentration on the optical properties, namely, photoluminescence emission, is measured and discussed. The oxides exhibit higher PL intensity with the Eu 3+ ion concentration and strong orange emission at 589 nm ( 5 D 0 – 7 F 1 ) corresponding to the magnetic dipole transition.