Metals (later the Institute for Materials Science), he started to build up the Ðrst research group on Applied Surface and Interface Analysis in Materials Science in Germany in 1972, using Auger Electron Spectroscopy (with a PHI-TFA instrument) and ion sputtering for depth proÐling to study surface and grain boundary segregation. In the mid-1970s, his group succeeded in the Ðrst experimental determination of a bulk di †usivity based on precise measurement and evaluation of surface segregation kinetics with record low di †usion constants down to 10~22 m2 s~1. Today, this method is widely used and is a textbook example of di †usion measurements.
In order to Ðnd ways to improve the corrosion and oxidation resistance of solid materials, his further research during the 1980s was focused on corrosion and oxidation of alloys and wear-resistant hard nitride coatings. Major contributions were the elaboration of the mechanisms of passive layer formation and pitting corrosion in stainless steels, and the role of segregation and di †usion in selective oxidation of alloys and nitride coatings by means of XPS, AES and depth proÐling. Systematic work on depth proÐling of bilayer and multilayer structures in nanometre dimensions resulted in an improved knowledge of the conditions and correct interpretation of sputter depth proÐles.