XPS depth profiling of Al/Si ratios in three kinds of zeolite powders was c
onducted by both destructive and non-destructive methods. Destructive profi
ling with Ar+ sputtering gave Al/Si 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 Na/Si profile. Analysis of the inelastic peak shape gave qualitative bu
t undoubted information on the in-depth profile. Analysis using synchrotron
radiation as an energy-tunable excitation source below 1000 eV revealed th
e 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
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