Size effect in luminescent properties of LiNdP4O12 nanocrystals

The LiNdP4O12 nanocrystals were synthesized using co-precipitation method. The grain size of the nanocrystals was controlled by heat treatment. The average grain size was determined from XRD analysis and confirmed by TEM images to be in range 42-240 nm. Impact of the average grain size on the luminescent properties of LiNdP4O12 nanocrystals was investigated. With increasing grain size the luminescence ratio F-4(3/2) -> I-4(9/2) to F-4(3/2) -> I-4(11/2) decreases due to the reabsorption of resonant luminescence F-4(3/2) -> I-4(9/2) transition. A significant enhancement of decay rate of F-4(3/2) was observed. Both of the effects are discussed in terms of enhancement of diffusion rate with increasing the size of nanocrystals. (C) 2014 Elsevier B.V. All rights reserved.