title: Irreversibility transition of colloidal polycrystals under cyclic deformation.
abstract: Cyclically loaded disordered particle systems, such as granular packings and amorphous media, display a non-equilibrium phase transition towards irreversibility. Here, we investigate numerically the cyclic deformation of a colloidal polycrystal with impurities and reveal a transition to irreversible behavior driven by the displacement of dislocations. At the phase transition we observe enhanced particle diffusion, system size effects and broadly distributed strain bursts. In addition to provide an analogy between the deformation of amorphous and polycrystalline materials, our results allow to reinterpret Zener pinning of grain boundaries as a way to prevent the onset of irreversible crystal ordering.
authors.affiliation: COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O.Box 11100, FI-00076 Aalto, Espoo, Finland.
authors.forename: Pritam Kumar
authors.initials: PK
authors.lastname: Jana
authors.affiliation: COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O.Box 11100, FI-00076 Aalto, Espoo, Finland.
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Alava
authors.affiliation: COMP Centre of Excellence, Department of Applied Physics, Aalto University, P.O.Box 11100, FI-00076 Aalto, Espoo, Finland.|Center for Complexity and Biosystems, Department of Physics, University of Milano, via Celoria 16, 20133 Milano, Italy.|ISI Foundation, Via Alassio 11/C, 10126, Torino, Italy.|CNR-ICMATE, Via R. Cozzi 53, 20125, Milano, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zapperi