XPS depth profiling of powdered materials

XPS depth profiling of AlrSi ratios in three kinds of zeolite powders was conducted by both destructive and non-destructive methods. Destructive profiling with Arq sputtering gave AlrSi profiles consistent with those found by non-destructive methods, although the results pointed out possible errors due to preferential sputtering that in fact caused a serious distortion of the NarSi profile. Analysis of the inelastic peak shape gave qualitative but undoubted information on the in-depth profile. Analysis using synchrotron radiation as an energy-tunable excitation source below 1000 eV revealed the topmost surface composition but could not detect the compositional change in deeper regions. It was concluded that to minimize analytical errors, a combination of the above methods is needed for materials of such complexity. q1999 Elsevier Science B.V. All rights reserved