Synthesis and optical properties of Eu<SUP>3</SUP><SUP>+</SUP> and Tb<SUP>3</SUP><SUP>+</SUP> doped Gd<SUB>2</SUB>O<SUB>3</SUB> nanotubes

Lanthanide doped oxides nanotubes have novel physical, chemical, optical and structural properties, and are recently under extensive investigation for application in biology labeling and magnetic resonance imaging contrast enhancement. We report here the synthesis of Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> doped Gd(OH)<SUB>3</SUB> nanotubes by simple hydrothermal technique and subsequently annealing to get its corresponding doped Gd<SUB>2</SUB>O<SUB>3</SUB> oxide tubular nanostructures. Structure determination reveals that Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> ions effectively incorporate into the lanthanide host. Microscopy characterization illustrates that both type of tubular structures are uniformly distributed, and have straight and smooth morphology as well. Photoluminescence measurement demonstrates the strong red and green emissions through UV excitation with larger life time. The influence of dopants activation on Raman spectra is represented. Our results suggest that Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> doped Gd<SUB>2</SUB>O<SUB>3</SUB> nanotube structures are useful for promising labels and biomedicines