Substantial planar plastic anisotropy in inorganic Mg3Bi2 single crystals

TY Zhang and J Yan and J Ke and P Zhao and YX Zhou and YF Zhou and S Ye and Y Xu and BP Ma and SH Chen and JX Cheng and JH Chen and ZY Yao and J Zhang and F Cao and LJ Zhang and J Mao and YH Fu and Q Zhang, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 122, e2516449122 (2025).

DOI: 10.1073/pnas.2516449122

Elucidating the fundamental microscopic mechanisms governing plastic deformation is crucial for the rational design of functional materials with tailored mechanical properties. Recent advances in Mg3Bi2-based thermoelectric materials have revealed exceptional room-temperature ductility in these compounds. However, the origin of their plastic behavior remains elusive. Herein, we report a pronounced in-plane plastic anisotropy in single-crystalline Mg3Bi2. Micropillar compression reveals that the observed anisotropy is critically dependent on the activation of single versus double slip systems, and superior plastic deformability can be achieved once the double slip system is activated. The interatomic potential for Mg3Bi2 was developed via the machine learning approach, and molecular dynamics simulations establish that the crystallographic orientation-dependent activation of competing slip systems constitutes the fundamental origin of the plastic anisotropy in Mg3Bi2. Additionally, our study demonstrates that pyramidal < a > dislocations play a crucial role in the plasticity of Mg3Bi2.

Return to Publications page