The detection of rare earth impurities in ionic materials by X-ray-stimulated luminescence

Abstract

The application of X-ray-stimulated luminescence to the detection of trivalent rare earth impurities in ionic materials is discussed. Characteristic luminescent wavelengths allow the identification of individual rare earths. The lower limit of impurity detectable in the particular case of the fluorides is found to be about 0.01 ppm if no positive identification of the rare earth ion is required. This is increased to 1 ppm when positive identification of the specific impurity is required. The application of the technique to the assessment of single crystals and the appropriate starting material is discussed.