title: Nanoscale Skyrmions in a Nonchiral Metallic Multiferroic: Ni2MnGa.
abstract: Magnetic skyrmions belong to a set of topologically nontrivial spin textures at the nanoscale that have received increased attention due to their emergent behavior and novel potential spintronic applications. Discovering materials systems that can host skyrmions at room temperature in the absence of external magnetic field is of crucial importance not only from a fundamental aspect, but also from a technological point of view. So far, the observations of skyrmions in bulk metallic ferromagnets have been limited to low temperatures and to materials that exhibit strong chiral interactions. Here we show the formation of nanoscale skyrmions in a nonchiral multiferroic material, which is ferromagnetic and ferroelastic, Ni2MnGa at room temperature without the presence of external magnetic fields. By using Lorentz transmission electron microscopy in combination with micromagnetic simulations, we elucidate their formation, behavior, and stability under applied magnetic fields at room temperature. The formation of skyrmions in a multiferroic material with no broken inversion symmetry presents new exciting opportunities for the exploration of the fundamental physics of topologically nontrivial spin textures.
authors.affiliation: Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Charudatta
authors.initials: C
authors.lastname: Phatak
authors.affiliation: Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.
authors.forename: Olle
authors.initials: O
authors.lastname: Heinonen
authors.affiliation: Department of Materials Science and Engineering, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Marc
authors.initials: M
authors.lastname: De Graef
authors.affiliation: Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States.|Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Amanda
authors.initials: A
authors.lastname: Petford-Long
keywords: Lorentz transmission electron microscopy; Skyrmions; multiferroic material