4 November 2025 - New publication in Acta Materialia

Stress-induced amorphization has been proposed as a deformation mechanism in ceramics, semiconductors, and geological materials, but direct evidence and boundary conditions for its activation remained limited. Using  systematic variations in Fe content show that iron suppresses amorphization and therefore enhances brittle behavior at low temperature. This result stands in clear contrast with high-temperature rheological data, where Fe is known to facilitate dislocation motion and ductility. The finding highlights the temperature dependence of the role of iron in olivine rheology, and suggests that amorphization may constitute an effective deformation mode under high stresses when conventional plasticity is kinetically restricted.

These results provide direct nanoscale evidence for a deformation regime relevant to cold mantler lithospheric environments, subduction interfaces, and brtittle ductile trnasition, while offering a new framework for tuning mechanical properties in hard crystalline materials through grain-boundary character and composition control.

To learn more:

I. Ul Haq, P. Cordier, K. Gouriet, J. Furstoss, A. Kashiwar, P. Baral, A. Orekhov, S. Koizumi, C. Bollinger, L. Delannay, P. Carrez, T. Pardoen, D. Schryvers & H. Idrissi (2026) Stress-induced amorphization promotes grain boundary sliding in olivine. Acta Materialia, 303, 121697. https://doi.org/10.1016/j.actamat.2025.121697