Bi-functional NaLuF₄:Gd³⁺/Yb³⁺/Er³⁺ nanocrystals: hydrothermal synthesis, optical and magnetic properties

Abstract

Magnetic-fluorescent lanthanide doped sodium lutetium fluoride (NaLuF₄:Yb³⁺/Er³⁺/Gd³⁺) nanocrystals were synthesized via facile hydrothermal method by varying concentration of Gd³⁺. Powder X-ray powder diffraction (PXRD), scanning electron microscopy (SEM),transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), particle size by dynamic light scattering (DLS),photoluminescence (PL) and magnetic studies were used to characterize the structural, optical and magnetic properties of these nanocrystals. Powder X-ray diffraction results signified good crystallinity and effective doping in sodium lutetium fluoride nanocrystals. The SEM and TEM micrographs defined their flower like morphology. The EDS was performed to investigate the presence of dopant. The emission intensities of the prepared samples are strongly controlled by particle sizes which are influenced by co-doping NaLuF₄ nanocrystals with varying concentration of Gd³⁺. Besides the efficient optical properties, Gd³⁺ doped NaLuF₄ nanocrystals exhibited paramagnetic behavior at room temperature with magnetization of up to 8.24× 10^-3 emu g^-1 at 15 kOe.