Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 23: Poster session

MM 23.11: Poster

Dienstag, 26. Februar 2008, 14:45–18:00, Poster B

Temperature dependence of elastic constants for the metallic glass Pd₄₀Ni₄₀P₂₀ — •Thomas Koeppe, Dennis Bedorf, and Konrad Samwer — 1. Physikalisches Institut Universität Göttingen, Germany

We have measured the elastic constants of bulk amorphous Pd₄₀Ni₄₀P₂₀ in the temperature range from 2 K to 300 K. The measuring technique was the ultrasonic pulse echo method with a frequency of 6 MHz. With decreasing temperature a linear increase of the elastic constants is found. At lower temperatures an increasing deviation from the straight line is observed. The Poisson ratio shows a linear decrease with decreasing temperature and deviates from that behavior at low temperatures also. This behavior is qualitatively the same as for single crystals and follows a T^3/2 - law down to our lowest temperature. The measured loss is very small at low temperatures and depends mainly on the bonding agent. So bulk amorphous metals are transparent for ultra sound at low temperatures. This work was supported financially by DFG, SFB 602 and Leibniz Programm.