Max-Planck-Institut für Eisenforschung GmbH, 40237 Düsseldorf, Germany.
Institute of Physics (IA), RWTH Aachen University, Sommerfeldstraße 14, 52056 Aachen, Germany.
Phys Rev Lett. 2018 Jul 6;121(1):015702. doi: 10.1103/PhysRevLett.121.015702.
The unique combination of atomic-scale composition measurements, employing atom probe tomography, atomic structure determination with picometer resolution by aberration-corrected scanning transmission electron microscopy, and atomistic simulations reveals site-specific linear segregation features at grain boundary facet junctions. More specific, an asymmetric line segregation along one particular type of facet junction core, instead of a homogeneous decoration of the facet planes, is observed. Molecular-statics calculations show that this segregation pattern is a consequence of the interplay between the asymmetric core structure and its corresponding local strain state. Our results contrast with the classical view of a homogeneous decoration of the facet planes and evidence a complex segregation patterning.
原子探针层析成像技术的原子尺度组成测量、皮米分辨率的像差校正扫描透射电子显微镜原子结构测定以及原子模拟揭示了晶界面角连接处的特定线性偏析特征。更具体地说，观察到的是沿特定类型的面角连接处核心的不对称线偏析，而不是面角的均匀修饰。分子静力学计算表明，这种偏析模式是不对称核心结构与其相应局部应变状态相互作用的结果。我们的结果与面角均匀修饰的经典观点形成对比，并证明了复杂的偏析模式。
