Alert Zenón, RicardTierno, PietroCasademunt i Viader, Jaume2018-01-092018-01-092017-12-050027-8424https://hdl.handle.net/2445/118933Mixed-order phase transitions display a discontinuity in the order parameter like first-order transitions yet feature critical behavior like second-order transitions. Such transitions have been predicted for a broad range of equilibrium and nonequilibrium systems, but their experimental observation has remained elusive. Here, we analytically predict and experimentally realize a mixed-order equilibrium phase transition. Specifically, a discontinuous solid-solid transition in a 2D crystal of paramagnetic colloidal particles is induced by a magnetic field HH. At the transition field HsHs, the energy landscape of the system becomes completely flat, which causes diverging fluctuations and correlation length ξ∝|H2−H2s|−1/2ξ∝|H2−Hs2|−1/2. Mean-field critical exponents are predicted, since the upper critical dimension of the transition is du=2du=2. Our colloidal system provides an experimental test bed to probe the unconventional properties of mixed-order phase transitions.4 p.application/pdfeng(c) Alert, Ricard et al., 2017Transformacions de fase (Física estadística)Fenòmens crítics (Física)Col·loidesPhase transformations (Statistical physics)Critical phenomena (Physics)Colloidsinfo:eu-repo/semantics/article6748692018-01-09info:eu-repo/semantics/openAccess29158388