[Zurück]

J. Schnöller, R. Wiesinger, C. Kleber, U. Hilfrich, M. Schreiner, H. Hutter:
"TOF-SIMS investigations on weathered silver surfaces";
Analytical and Bioanalytical Chemistry, 390 (2008), 6; S. 1543 - 1549.

Silver-coated quartz crystal microbalance (QCM) disks were treated under different environmental conditions (including changes in parameters such as relative humidity (%RH) and SO₂H₂S content) in atmospheres of synthetic air and pure N₂ for 24 h in a weathering chamber. The corroded surfaces were subjected to depth profiling by a time of flight (TOF) secondary ion mass spectrometry (SIMS) instrument, equipped with a Bi+ analysis gun and Cs+ sputter gun. The evaluation of the in-depth distribution of several elements and species provides evidence for the formation of a corrosion layer containing Ag₂SO₃, even in the absence of oxidizing agents, such as H₂O₂ or NO₂. Furthermore it could be elucidated that the thickness of the formed Ag₂SO₃ layer does not depend on the SO₂ concentration but rather on the humidity and oxygen content of the ambient atmosphere. In weathering experiments in atmospheres composed of synthetic air, humidity, and H₂S, the presence of different oxygen species (surface and bulk) and silver sulfide could be detected by TOF-SIMS depth profiling experiments. The obtained results for both acidifying gases are in good correlation with the corresponding tapping mode atomic force microscopy (TM-AFM) investigations and in situ QCM measurements.

TOF-SIMS , Depth profiling, QCM , TM-AFM, Weathering , Corrosion

http://dx.doi.org/10.1007/s00216-007-1719-8