Berlin 2012 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 17: Poster Session

MM 17.80: Poster

Montag, 26. März 2012, 17:00–19:00, Poster B

Study of the EFGs at both M- and A-sites in Zr₂InC and Hf₂InC using γ-γ angular correlation spectroscopy — •Daniel Jürgens¹, Michael Uhrmacher¹, Ulrich Vetter¹, Hans Hofsäss¹, Jose Mestnik-Filho², and Michel W. Barsoum³ — ¹Georg-August-Universität Göttingen, II. Physikalisches Institut, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany — ²Instituto de Pesquisas Energeticas e Nucleares, 05422-970 São Paulo, Brazil — ³Dep. Mat. Science and Eng. Drexel University, Philadelphia, PA 19104, USA

The compounds Zr₂InC and Hf₂InC belong to the class of MAX phases, which are known for their metallic and ceramic characteristics. Due to their unusual set of properties, these phases have been studied intensively in recent years with the aim to find new high-performance materials. Since most applied techniques only allow a macroscopic insight, the perturbed angular correlation (PAC) was used to determine the local environment of inserted probes on atomic scale. Radioactive ¹¹¹In and ¹⁸¹Hf ions were implanted into the samples to measure characteristic electric field gradients, EFGs, at a certain site. The A-site EFG was investigated by using the ¹¹¹In isotope and the M-site by ¹⁸¹Hf probes. In this study we report on the different annealing behaviors of In- and Hf-probes in Zr₂InC and Hf₂InC. We show that the A-site EFG strengths are nearly identical (ν_Q≈ 350 MHz), while the EFGs for the M-site are unequal. We compare the experimental results with predictions from density functional theory calculations and give reasons why the A- and M-site EFGs are in such a way dissimilar.