Eu3+ as a marker for formation of core-shell system: YVO4:SiO2

Eu 3+ doped in core and shell (YVO 4 :SiO 2 ) nanoparticles show luminescence peaks corresponding to magnetic and electric dipole transitions of Eu 3+ . When Eu 3+ ions occupy Y 3+ sites, Eu 3+ ions are surrounded by eight O 2− ions, which is highly asymmetric ( D 2d ). This asymmetric environment can be used to see amount of Eu 3+ ions present in Y 3+ sites. When Eu 3+ ions are present in shell (SiO 2 ), luminescence intensity is very weak. On further annealing, luminescence intensity increases due to diffusion of Eu 3+ ions towards to YVO 4 core through pores of SiO 2 . Distribution of Eu 3+ in core and shell are supported by lifetime studies.