A novel experimental approach to determine the absolute grain boundary energy

Abstract

The shape of a 90° ⟨112⟩ tilt boundary in bismuth and a boundary in zinc bicrystals was analyzed, which had developed during annealing at elevated temperatures when the boundary had migrated due to the magnetic free energy density difference across the boundary while the boundary was fixed on the lateral sample surfaces. After annealing in an external magnetic field the 90°⟨112⟩ boundary in bismuth became faceted. This evidenced the pronounced anisotropy of boundary energy with respect to its inclination. The random (non-tilt) boundary in the Zn bicrystal assumed a curved shape after magnetic annealing. Evaluation of the curvature of the boundary segments with the highest constant curvature permitted estimation of the upper limit of the energy of differently inclined boundary sections in Zn: 0.27 and 0.41 J m⁻².

Keywords:

• grain boundary energy
• grain boundary migration
• magnetic driving force
• bicrystal

Acknowledgements

The authors express their gratitude to the Deutsche Forschungsgemeinschaft for financial support (Grant MO 848/12-2). Part of this work was performed at the National High Magnetic Field Laboratory, which is supported by NSF Cooperative Agreement No. DMR-0084173, by the State of Florida and by the DOE. Part of this work has been supported by EuroMagNET under the EU contract RII3-CT-2004-506239 and performed at the High Magnetic Field Laboratory of Radboud University, Nijmegen, the Netherlands.