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Updated: Sep 18, 2025
Probing the Structure and Dynamics of Interfacial Water with Scanning Tunneling Microscopy and Spectroscopy
Published on: May 27, 2018
A new twinning mechanism induced by solute electronic structures
Wenjin Zheng1, Huasheng Lei1, Wei Lai1
1State Key Laboratory of Photocatalysis on Energy and Environment, College of Chemistry, Fuzhou University, Fuzhou, Fujian 350002, P. R. China. yuzyemlab@fzu.edu.cn.
Abstract:
Twin boundaries are frequently observed in polycrystalline materials, significantly influencing their stability and mechanical properties. In this study, we reveal a previously unidentified growth twinning mechanism induced by solute segregation, wherein changes in local electronic structure dictate twin formation. Aberration-corrected scanning transmission electron microscopy, combined with energy-dispersive spectroscopy, demonstrates that the interfacial segregation of W atoms triggers growth twinning in (V, W)C precipitates. Notably, the formation of twin boundaries is highly sensitive to the local W concentration, with a high segregation level of up to 50 at% promoting twin formation, whereas a lower concentration of 20 at% suppresses it. First-principles calculations further reveal that this twinning mechanism originates from a local coordination shift, transitioning from the octahedral geometry characteristic of VC to the mirror-symmetric trigonal coordination of W2C at elevated W concentrations. These findings provide a deeper understanding of solute-induced twinning and offer a pathway for precise control of twin events in crystalline materials.
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