Determination of small concentrations of hafnia in zirconia by selective excitation energy dispersive X-ray emission spectrometry

An energy dispersive X-ray fluorescence method is described for the determination of small concentrations of hafnia in zirconia. Bromine K X-rays from a secondary target in the form of a thick KBr pellet (excited by primary X-rays from a tungsten target X-ray tube) have been used to excite the analyte Hf L-lines selectively without exciting the matrix Zr K X-rays. The Hf L intensity vs. concentration relation was found to be linear in the concentration range 0.0–2.0 percent. The method gave a minimum detection limit of 45 ppm for 10 min (live) counting time. The results are discussed and the performance of this method is compared with those of WDXRF methods.