Biomedical subjects

M Leisch

Publications and source records attributed to M Leisch.

2 recordsLinked to original sources

PubMed1995

Position sensitive atom probe study of segregation in molybdenum alloys.

Three dimensional atom-probe measurements have been carried out to study the segregation behaviour of Mo(x)W((1-x)) alloys (x = 0.9; 0.75; 0.5; 0.25). As predicted from alloy thermodynamics, on in situ annealed specimens a significant surface enrichment of molybdenum has been observed. For alloys with tungsten contents above 25% the composition profiles measured are in a good agreement with the theoretical predictions. The positive regular solution parameter of this binary system gives reason for a random distribution of alloy components. In the three-dimensional reconstructions local agglomerations and combined features of tungsten atoms are to observe in alloys with Mo as major component.

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PubMedDate not supplied

Study on tip-substrate interactions by STM and APFIM.

Processes occurring at the interface of two materials coming in contact, separating or moving with respect to each other have been studied with the scanning tunnelling microscope (STM) and atom-probe (AP) field ion microscopy (APFIM). STM probe tips have been first characterised by field ion microscopy (FIM), brought into well-defined contact in the STM and afterwards inspected by time-of-flight AP. The results from mechanical contact and indentation experiments, showing material transfer and neck formation, are in reasonable good agreement with computer-based simulations on metal tip-surface interactions.

Journal Article↗