Dresden 2020 – wissenschaftliches Programm
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MM 23.2: Vortrag
Dienstag, 17. März 2020, 12:00–12:15, IFW A
Structure and local electrical resistivity in copper grain boundaries — •Hanna Bishara, Matteo Ghidelli, and Gerhard Dehm — Max-Planck-Institut für Eisenforschung
Grain boundaries (GBs) are among the most significant microstructure defects influencing mechanical and functional properties of materials. The atomic structure at a GB is determined by the crystallography, composition and temperature as well as by the relative orientation between neighbouring grains. Still, the impact of structural characteristics of the GB on the various physical properties of the materials is not fully understood. Here, we aim to correlate the structural and electrical properties of GBs through in-situ local electrical measurements on well-defined GB planes.
To this aim Cu thin films are sputter-deposited and annealed to induce grain growth with final grain sizes of a few tens of micrometers. EBSD is used to identify the GB plane. Subsequently, FIB machining is employed to isolate specific GBs and their corresponding grains from the rest of film, to probe the electrical resistivity. The electrical resistivity measurements are conducted in-situ through 4-point-probe measurements using micro-manipulators and a nV sensitive voltage-meter. We report, for the first time, on direct resistivity measurements of different coincidence site lattice (CSL) and low angle GBs in Cu. Measured resistivities span for more than order of magnitude and match the predicted values by simulations. Deviation from predicted values are related to Ga segregation into GBs. The results provide a solid relation between structure and electrical properties of GBs.