Mild solvothermal synthesis and luminescent properties of the complex fluorides KMgF3:Eu and KZnF3:RE (RE = Eu, Ce)

The complex fluorides KMF3:Re (M = Mg, Zn; Re = Eu, Ce) were solvothermally synthesized at 180 °C and characterized by means of X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared spectroscopy (IR) and spectrofluorometer. In the emission spectrum of KMgF3:Eu powders, there is one sharp line emission located at 360 nm, which is arisen from f→f (6P7/2→8S7/2) transition of Eu2+ in KMgF3 lattice. The excitation spectrum of KMgF3:Eu powders monitored at 360 nm emission has only one broad peak maximum at about 250 nm. In the emission spectrum of KZnF3:Eu, there is one sharp line emission located at 360 nm (6P7/2→8S7/2 transition of Eu2+) and one broad range of 370–550 nm with a maximum center located at 461 nm, which is arisen from d→f (4f65d→8S7/2) transition of Eu2+. The excitation spectrum of KZnF3:Eu monitored at 360 nm emission has one broad peak maximum at about 253 nm. The typical doublet 5d–4f emission peaks of Ce3+ in KZnF3 powders are shown.