Fracture and commercial float glass surfaces have been analyzed in a C
ameca IMS-3f spectrometer using O-18-bombardment. Sample charging was
controlled through the use of different combinations of a gold grid an
d thin gold coating. Depth profiles have been quantified with relative
sensitivity factors (RSFs) that were determined from fracture surface
s of float glasses of known composition. The sodium and potassium RSFs
have been found to be more sensitive to the method of charge compensa
tion than the RSFs of the other elements in the glass. The integrity o
f the sodium signal is not guaranteed by the presence of a grid on the
sample surface. Depth profiles of fracture surfaces show unexpected g
radients that can extend to 100 nm, complicating the interpretation of
profiles obtained from manufactured surfaces. The calculation of the
atomic fraction of all the elements in the glass is difficult within a
pproximately 300 nm of the surface owing to effects from the measured
oxygen signal. Fortunately, the composition of the glass as expressed
in mole percent of the oxides is more reliable, but still not free of
artifacts. The results of these studies and those performed on similar
glasses and materials in other laboratories suggest that, regardless
of the primary beam, fracture surface analysis should precede the anal
yses of treated surfaces, especially if quantitative information is re
quired within 100 nm of the surface.