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Observation of Robust Néel Skyrmions in Metallic PtMnGa
Author(s) -
Srivastava Abhay K.,
Devi Parul,
Sharma Ankit K.,
Ma Tianping,
Deniz Hakan,
Meyerheim Holger L.,
Felser Claudia,
Parkin Stuart S. P.
Publication year - 2020
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201904327
Subject(s) - skyrmion , tetragonal crystal system , condensed matter physics , materials science , spintronics , point reflection , metal , crystallography , physics , crystal structure , ferromagnetism , metallurgy , chemistry
Over the past decade the family of chiral noncollinear spin textures has continued to expand with the observation in metallic compounds of Bloch‐like skyrmions in several B20 compounds, and antiskyrmions in a tetragonal inverse Heusler. Néel like skyrmions in bulk crystals with broken inversion symmetry have recently been seen in two distinct nonmetallic compounds, GaV 4 S 8 and VOSe 2 O 5 at low temperatures (below ≈13 K) only. Here, the first observation of bulk Néel skyrmions in a metallic compound PtMnGa and, moreover, at high temperatures up to ≈220 K is reported. Lorentz transmission electron microscopy reveals the chiral Néel character of the skyrmions. A strong variation is reported of the size of the skyrmions on the thickness of the lamella in which they are confined, varying by a factor of 7 as the thickness is varied from ≈90 nm to ≈4 µm. Moreover, the skyrmions are highly robust to in‐plane magnetic fields and can be stabilized in a zero magnetic field using suitable field‐cooling protocols over a very broad temperature range to as low as 5 K. These properties, together with the possibility of manipulating skyrmions in metallic PtMnGa via current induced spin–orbit torques, make them extremely exciting for future spintronic applications.