Regensburg 2004 – wissenschaftliches Programm
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M: Metallphysik
M 32: Grenzfl
ächen und Wachstum
M 32.1: Vortrag
Donnerstag, 11. März 2004, 16:30–16:45, H4
Interface Structure and Segregation Effects of Nanocrystalline PdZr in Dependence of Temperature — •H. Weigand1, W. Sprengel1, T. Wejrzanowski2, C. E. Krill3, R. Röwer1, M. Kelsch4, and H.-E. Schaefer1 — 1Inst. f. Theor. u. Angew. Phys., Univ. Stuttgart, D-70569 Stuttgart — 2Faculty of Mat. Science. a. Engin., Warsaw Univ. of Techn., 02-507 Warszawa, Poland — 3Techn. Phys., Univ. d. Saarlandes, D-66041 Saarbrücken — 4MPI f. Metallf., D-70569 Stuttgart
Grain growth of n-PdZr alloys is expected to be reduced by segregation of Zr in the grain boundaries. Positron annihilation spectroscopy was employed to study this effect and the temperature dependence of the interface structure, showing a decrease of the fraction of nanovoids, the size of 10 to 15 missing atoms, upon isochronal annealing up to 1100 K.
Temperature dependent studies after annealing at 1100 K show a reversible increase of the mean positron lifetime with temperature due to a reversible change of the positron trapping behavior at interfacial free volumes. The variation of the interfacial composition with temperature is investigated.