Rapid non-destructive determination of thin films of platinum by particle back-scattering

Rutherford back-scattering of α-particles is used to determine trace amounts of thin films of platinum. The method is sensitive to 0.3 ng of platinum and the response is linear from at least 0.01 to 80 μg Pt cm^-2 of substrate surface area. Calibration with weighed standards reveals good accuracy and precision throughout the linear range. Up to at least 80 μg cm^-2, no matrix effects can be observed for platinum determinations on Mylar, carbon, glass, and glass or quartz coated with up to 0.5 μm thicknesses of tin oxide. Particle-induced x-ray emission spectra are included to show their utility in surface composition analysis. The analytical procedure for the determination of platinum is rapid and non-destructive, and requires minimal sample preparation.