Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 17: Postersession I
MM 17.34: Poster
Montag, 16. März 2015, 18:00–20:00, Poster E
Electric field gradients at M- and A-sites in 211 MAX-phases using perturbed angular correlation spectroscopy — Daniel Jürgens1, Michael Uhmacher1, Ulrich Vetter1, Matthias Nagl1, •Hans Hofsäss1, Jose Mestnik-Filho2, and Michael W. Brasoum3 — 1Georg-August-Universität Göttingen, II. Physikalisches Institut, Göttingen, Germany — 2Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo, Brazil — 3Department of Material Science and Engineering, Drexel University, PA, USA
Local magnetic fields and electric field gradients at the site of probe atoms in solids can be measured with hyperfine interaction techniques and allows the investigation of the local microstructure around M- and A-sites and possible magnetic properties of MAX-phase compounds, which are known for their metallic as well as their ceramic properties. Since most techniques only allow a macroscopic insight, the perturbed angular correlation (PAC) was used to determine the local environment of implanted probe atoms on atomic scale. Radioactive 111In and 181Hf ions, both decaying by a γ−γ cascade, were implanted into Zr2InC and Hf2InC and the electric field gradients (EFG) at a A-site (in) and M-sites (Hf) were measured after annealing the implantation damage. We report on the different annealing behavior observed for In and Hf probes. We compare the results with density functional theory calculations and give reasons for dissimilar EFGs at A- and M-sites. Further results for other 211 MAX-phases (Ti2InC, Ti2AlC, V2AlC, Cr2AlC, Nb2AlC, Ti2AlN,Cr2GeC, Ti2GeC,Nb2AsC, and Ti2SiC) are presented.