Regensburg 2010 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 37: MLT: Poster Session

TT 37.5: Poster

Donnerstag, 25. März 2010, 14:00–18:00, Poster A

Low temperature vibrating reed measurements of Zr based metallic glasses — •C. Adler, W. Mohr, T. Peichl, and G. Weiss — Physikalisches Institut, Karlsruher Institut für Technologie 76128 Karlsruhe

The low temperature thermal and acoustic behavior of glasses, dielectric or metallic, is dominated by two-level systems caused by the tunneling of small groups of atoms between two almost equivalent sites. Specific distributions of the relevant parameters are suggested by the well established tunneling model. Acoustic measurements of various superconducting metallic glasses demonstrate that conduction electrons not only drastically change the dynamics of tunneling systems as compared to insulating glasses but also seem to influence the apparent density of states of the tunneling systems. The advent of bulk metallic glasses (BMG) considerably facilitates acoustic experiments. Our vibrating reed measurements of the BMG Zr₅₉Ti₃Cu₂₀Ni₈Al₁₀ and the splat cooled metallic glass Zr₆₅Al_7.5Cu_27.5 reveal interesting differences in the internal friction which presumably reflect the quite different cooling rates in the preparation procedures of the two metallic glasses.