Direct observation of nanoindentation-induced punching-out of prismatic dislocation loops in tungsten
Florian Tropper and Takahito Ohmura
Phys. Rev. Materials 10, L090601 (2026) - Published 14 September, 2026
The authors have successfully induced and characterized a channel-like deformation mechanism in pure tungsten, providing a new experimental pathway to evaluate irradiation damage in future nuclear fusion reactors. While this phenomenon, where atomic layers slide rigidly like a solid cylinder being forced through a tight tube, is known to occur as a destructive byproduct of intense radiation inside fusion environments, it has previously been highly difficult to isolate and study in a controlled manner. In this work, they overcame this challenge by precisely pressing a microscopic tip into a specifically oriented tungsten single-crystal. Using advanced electron microscopy techniques, they studied the resulting atomic displacements and determined the channel-like deformation for the first time in this crystal structure. This opens a new avenue to study defect formation and propagation, critical for understanding fundamental plastic yielding and analyzing structurally identical irradiation-induced defects.
