Eu3+-doped LaPO4 and LaAlO3 nanosystems and their luminescence properties

Eu3+ ion-doped LaPO4 nanowires or nanorods have been successfully synthesized by a simple hydrothermal method. The influence of varying the hydrothermal and subsequent sintering conditions on the morphology and structure of the LaPO4 host has been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). For comparison, the Eu3+ ions were also doped into monoclinic monazite LaPO4 nanoparticles and perovskite LaAlO3 nanoparticles. The relative intensities of the emission lines of the LaPO4:Eu3+ nanosystems were essentially independent of their shape. The optimal doping concentrations in the monoclinic LaPO4 and perovskite LaAlO3 nanosystems were determined to be about 5.0 and 3.5 mol%, respectively. Under appropriate UV-radiation, the red light emitted from LaAlO3:Eu3+ (3.5 mol%) was brighter than that from LaPO4:Eu3+ (5.0 mol%) nanomaterial, resulting from differences in their spin-orbit couplings and covalence, which indicates that the nanoscale LaAlO3 is a promising host material for rare earth ions.