Lattice instability criterion is linear in stresses for any stress state in a material.
Significance and Impact
Reveals new processing routes in solid-solid phase transformations. Enables navigating phase transformation to access novel states or high-pressure phases at lower stresses and pressures.
- High-throughput calculations were performed to sample a multidimensional space of deformations in materials with varied stress states.
- Properties were computed versus complex stress and strain states; and lattice instabilities were found.
- Instability criterion was analyzed using tensor algebra: Linearity vs. stress component was identified.
- Competition of instabilities serves for phase selection, not free-energy minima in usual processing.
Nikolai A. Zarkevich, H. Chen, V.I. Levitas, and Duane D. Johnson, Phys. Rev. Lett. 121, 165701 (2018). DOI: 10.1103/PhysRevLett.121.165701