Modifying crystal phase, shape, size, optical and magnetic properties of monodispersed multifunctional NaYbF4 nanocrystals through lanthanide doping

In this paper, a simple lanthanide (Ln) doping route for modifying the crystal structure including crystal phase, shape, size and physics properties such as up conversion (UC) and magnetic properties of monodisperse multifunctional NaYbF4 nanocrystals is demonstrated. The results revealed that the crystal phase transformation from cubic to hexagonal phase, shape evolution from one-dimensional (rods) to zero-dimensional (nanoparticle) and size transition from microscale to nanoscale can be readily tuned. Moreover, these nanocrystals doped with different Gd3+ concentrations exhibit multi-functionality, including tunable UC emissions colours and paramagnetic properties, which making them potentially applicable in the biological field as biolabels, bioseparation, magnetic resonance imaging (MRI), and optical-magnetic dual modal nanoprobes in biomedical imaging. It is also expected that the doping-induced structure and physical properties transformation can be applied to other NaLnF(4) nanocrystals.