Fig. 1From: Excretable, ultrasmall hexagonal NaGdF4:Yb50% nanoparticles for bimodal imaging and radiosensitizationCharacterization of β-NaGdF4:Yb50%. a TEM and b HRTEM images show that the synthesized nanoparticles are uniform and monodisperse with a core diameter less than 5 nm; c size distribution determined from several TEM images. d XRD reveals the hexagonal crystal structure, which is the thermodynamically stable phase of the nanocrystalBack to article page