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.

8 pages, 4 figures

References in corpus (12)

• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• A new class of chiral materials hosting magnetic skyrmions beyond room temperature
• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
• Magnetic phase diagram of MnSi inferred from magnetization and ac susceptibility
• Capturing of a Magnetic Skyrmion with a Hole
• Modeling the momentum distributions of annihilating electron-positron pairs in solids
• Formation of a topological non-Fermi liquid in MnSi
• Real-Space and Reciprocal-Space Berry Phases in the Hall Effect of Mn${}_{1-\mathrm{x}}$Fe${}_{\mathrm{x}}$Si
• Giant generic topological Hall resistivity of MnSi under pressure
• Three real-space discretization techniques in electronic structure calculations
• Thermodynamics of point defects and diffusion mechanisms in B2-ordered compounds

Cited by in corpus (8)

• Symmetry breaking, slow relaxation dynamics, and topological defects at the field-induced helix reorientation in MnSi
• Stabilization mechanisms of magnetic skyrmion crystal and multiple-$Q$ states based on momentum-resolved spin interactions
• Defect Imaging and Detection of Precipitates Using a New Scanning Positron Microbeam
• Weak crystallization of fluctuating skyrmion textures in MnSi
• Kinetic small angle neutron scattering of the Skyrmion lattice in MnSi
• Ultra-high vacuum compatible preparation chain for intermetallic compounds
• Novel Data Analysis Tool for the Evaluation of Coincidence Doppler Broadening Spectra of the Positron-Electron Annihilation Line
• Compositional Studies of Metals with Complex Order by means of the Optical Floating-Zone Technique