TIME-OF-FLIGHT STATIC SECONDARY-ION MASS-SPECTROMETRY ANALYSIS OF SURFACE CONTAMINATION ON PT IR STANDARD MASS MATERIAL/

Static time-of-flight secondary ion mass spectrometry (TOF-SIMS) has b een used to characterize surface contaminants on a Pt-10% Ir alloy sam ple prescribed for fabrication of a prototype kilogram mass standard. The identification of various oxygenated and non-oxygenated hydrocarbo n adsorbates on the Pt-Ir surface provides a scenario for the increase in mass observed after standard cleaning procedures, and as a functio n of time. Static TOF-SIMS analysis suggests the catalytic activity of Pt plays a key role in the adsorption of organic solvents used in sta ndard cleaning procedures as well as adsorption of hydrocarbon species present in ambient laboratory air. (C) 1998 John Wiley & Sons, Ltd.