title: Positron spectroscopy of point defects in the skyrmion-lattice compound MnSi.
abstract: Outstanding crystalline perfection is a key requirement for the formation of new forms of electronic order in a vast number of widely different materials. Whereas excellent sample quality represents a standard claim in the literature, there are, quite generally, no reliable microscopic probes to establish the nature and concentration of lattice defects such as voids, dislocations and different species of point defects on the level relevant to the length and energy scales inherent to these new forms of order. Here we report an experimental study of the archetypical skyrmion-lattice compound MnSi, where we relate the characteristic types of point defects and their concentration to the magnetic properties by combining different types of positron spectroscopy with ab-initio calculations and bulk measurements. We find that Mn antisite disorder broadens the magnetic phase transitions and lowers their critical temperatures, whereas the skyrmion lattice phase forms for all samples studied underlining the robustness of this topologically non-trivial state. Taken together, this demonstrates the unprecedented sensitivity of positron spectroscopy in studies of new forms of electronic order.
authors.affiliation: Physik-Department, Technical University of Munich, 85748 Garching, Germany.|Heinz Maier-Leibnitz Zentrum, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Reiner
authors.affiliation: Physik-Department, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bauer
authors.affiliation: Heinz Maier-Leibnitz Zentrum, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Leitner
authors.affiliation: Physik-Department, Technical University of Munich, 85748 Garching, Germany.|Heinz Maier-Leibnitz Zentrum, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gigl
authors.affiliation: Institut für Strahlenphysik, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Anwand
authors.affiliation: Institut für Strahlenphysik, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany.
authors.forename: Maik
authors.initials: M
authors.lastname: Butterling
authors.affiliation: Institut für Strahlenphysik, Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wagner
authors.affiliation: Heinz Maier-Leibnitz Zentrum, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Kudejova
authors.affiliation: Physik-Department, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Pfleiderer
authors.affiliation: Physik-Department, Technical University of Munich, 85748 Garching, Germany.|Heinz Maier-Leibnitz Zentrum, Technical University of Munich, 85748 Garching, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Hugenschmidt