Fig. 2From: Synthesis and Luminescence Properties of Water Soluble α-NaGdF4/β-NaYF4:Yb,Er Core–Shell NanoparticlesXRD patterns of (a) the NaGdF4 core nanocrystals, and the NaGdF4/ NaYF4:Yb,Er core/shell (named C/S in the figure) nanocrystals with different reaction time, (b) 2 h, (c) 6 h, (d) 12 h, and (e) 24 h. (f) Standard data of β-NaYF4 (JCPDS 16-334). (g) Standard data of α-NaGdF4 (JCPDS 27-697)Back to article page