Effects of lutetium doping on the X-ray-excited luminescence properties of the tungstate Zn1−xLuxWO4

Polycrystalline samples in the lutetium-doped zinc tungstate system Zn1−x Lu x WO4 with 0 ≤ x ≤ 0.08 were synthesized using the coprecipitation method followed by thermal treatment at 1000 °C during 4 h. The polycrystalline samples were characterized by X-ray diffraction analysis, scanning electron microscopy (SEM), infrared spectroscopy, and luminescence analysis under X-ray excitation. Rietveld analyses were performed. The variation of the wolframite structure cell parameters in the range 0 ≤ x ≤ 0.05 were congruent with substitution of Zn2+ by Lu3+. SEM micrographs of the obtained samples presented improved crystallization with morphology depending on the lutetium fraction. The luminescence spectra obtained under X-ray excitation (E < 40 keV) were in the blue–green region, and their intensity increased with x up to x = 0.05. The differences in the intensities of the X-ray luminescence spectra could be related to additional cation vacancies resulting from substitution of Zn2+ by Lu3+.