title: Re-dispersion and film formation of GdVO4 :  Ln3+ (Ln3+ = Dy3+, Eu3+, Sm3+, Tm3+) nanoparticles: particle size and luminescence studies.
abstract: GdVO(4) : Ln(3+) (Ln(3+) = Dy(3+), Eu(3+), Sm(3+), Tm(3+)) nanoparticles are prepared by a simple chemical route at 140 °C. The crystallite size can be tuned by varying the pH of the reaction medium. Interestingly, the crystallite size is found to increase significantly when pH increases from 6 to 12. This is related to slower nucleation of the GdVO(4) formation with increase of VO(4)(3-) present in solution. The luminescence study shows an efficient energy transfer from vanadate absorption of GdVO(4) to Ln(3+) and thereby enhanced emissions are obtained. A possible reaction mechanism at different pH values is suggested in this study. As-prepared samples are well dispersed in ethanol, methanol and water, and can be incorporated into polymer films. Luminescence and its decay lifetime studies confirm the decrease in non-radiative transition probability with the increase of heat treatment temperature. Re-dispersed particles will be useful in potential applications of life science and the film will be useful in display devices.
authors.affiliation: Department of Physics, Manipur University, Canchipur, Imphal-795003, Manipur, India.
authors.forename: N
authors.initials: N
authors.lastname: Shanta Singh
authors.forename: R S
authors.initials: RS
authors.lastname: Ningthoujam
authors.forename: Ganngam
authors.initials: G
authors.lastname: Phaomei
authors.forename: S Dorendrajit
authors.initials: SD
authors.lastname: Singh
authors.forename: A
authors.initials: A
authors.lastname: Vinu
authors.forename: R K
authors.initials: RK
authors.lastname: Vatsa