From dislocation nucleation to dislocation multiplication in ceramic nanoparticle

Inas Issa (1, 2, 3) , Lucile Joly-Pottuz (1) , Jonathan Amodeo (1, 4) , David J Dunstan (5) , Claude Esnouf (1) , Julien Réthoré (2, 6) , Vincent Garnier (1) , Jérôme Chevalier (1) , Karine Masenelli-Varlot (1)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 LaMCoS - Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne]
3 MUL - Montanuniversität Leoben
4 IM2NP - Institut des Matériaux, de Microélectronique et des Nanosciences de Provence
5 QMUL - Queen Mary University of London
6 GeM - Institut de Recherche en Génie Civil et Mécanique

Magnesium oxide nanocubes are compressed along the [001] direction in situ in the transmission electron microscope. Incipient plasticity in the smaller samples is characterized by the nucleation of few 1 / 2 <110>{110} dislocations while a larger number of line defects is observed in larger nanocubes. Yield and flow stresses scattered stochastically above a minimum value varying as the inverse of the sample size. The upper bound is given by the reduced number of dislocation sources. Such size-dependent behaviour is justified by a detailed statistical analysis and is fully explained by the deformation mechanism.

Mots clés: In situ; TEM; compression; dislocation; mgo

Domaines: Mécanique des matériaux [physics.class-ph]

Inas Issa, Lucile Joly-Pottuz, Jonathan Amodeo, David J Dunstan, Claude Esnouf, et al.. From dislocation nucleation to dislocation multiplication in ceramic nanoparticle. Materials Research Letters, 2021, 9 (6), pp.278-283. ⟨10.1080/21663831.2021.1894253⟩. ⟨hal-03356913⟩