We are organizing a STATPHYS27 satellite workshop in Bariloche, 2-5 July 2019, on yielding in amorphous materials and related phenomena. https://yielding2019.sciencesconf.org/ Save the date!
I’m very happy and truly honored by the responsibility of becoming an Editor of Papers in Physics. This is a non-profit, accessible price, open-access journal, ran by physicists for physicists. Which further allows the “open review” treatment, that highlights not only the work done by authors but also by referees and editors.
The journal platform needs a touch of modernization, that’s true; but we’re working on it. The assignment of an official impact factor is expected soon and we will boost this journal up.
Magnetic domain wall motion is at the heart of new magnetoelectronic technologies and hence the need for a deeper understanding of domain wall dynamics in magnetic systems. In this context, numerical simulations using simple models can capture the main ingredients responsible for the complex observed domain wall behavior. We present a scalar field model for the magnetization dynamics of quasi-two-dimensional systems with a perpendicular easy axis of magnetization which allows a direct comparison with typical experimental protocols, used in polar magneto-optical Kerr effect microscopy experiments. We show that the thermally activated creep and depinning regimes of domain wall motion can be reached and the effect of different quenched disorder implementations can be assessed with the model. In particular, we show that the depinning field increases with the mean grain size of a Voronoi tessellation model for the disorder.
Phys. Rev. E 97, 062122 – Published 11 June 2018
The origin of the brittle-to-ductile transition, experimentally observed in amorphous silica nanofibers as the sample size is reduced, is still debated. Here we investigate the issue by extensive molecular dynamics simulations at low and room temperatures for a broad range of sample sizes, with open and periodic boundary conditions. Our results show that small sample-size enhanced ductility is primarily due to diffuse damage accumulation, that for larger samples leads to brittle catastrophic failure. Surface effects such as boundary fluidization contribute to ductility at room temperature by promoting necking, but are not the main driver of the transition. Our results suggest that the experimentally observed size-induced ductility of silica nanofibers is a manifestation of finite-size criticality, as expected in general for quasi-brittle disordered networks.
I have started a new fresh year in a new office and a new desk, this time as an stable researcher of CONICET (the Argentinean National Research Council). I’m joining a group of excellent people, the condensed matter theory group, at Centro Atómico Bariloche (Argentina), a great spot to do science. I’m grateful to the group for the welcoming and to all my previous hosts for a very soft and enriching postdoc path to my actual position. Thanks!
It has been a very long work, beautifully leaded by Alexandre the great, but finally it’s out there: the preprint of our review article on elastoplastic models for the deformation of amorphous solids. Since we begin a long edition path now, any comments and suggestions would be welcome! Enjoy! (arxiv:1708.09194)