A new class of chiral materials hosting magnetic skyrmions beyond room temperature

Abstract

Skyrmions, topologically protected vortex-like nanometric spin textures in magnets, have been attracting increasing attention for emergent electromagnetic responses and possible technological applications for spintronics. In particular, metallic magnets with chiral and cubic/tetragonal crystal structure may have high potential to host skyrmions that can be driven by low electrical current excitation. However, experimental observations of skyrmions have so far been limited to below room temperature for the metallic chiral magnets, specifically for the MnSi-type B20 compounds. Toward technological applications, it is crucial to transcend this limitation. Here we demonstrate the formation of skyrmions with unique spin helicity both at and above room temperature in a family of cubic chiral magnets: beta-Mn-type Co-Zn-Mn alloys with a different chiral space group from that of B20 compounds. Lorentz transmission electron microscopy (LTEM), magnetization, and small angle neutron scattering (SANS) measurements unambiguously reveal the formation of a skyrmion crystal under the application of magnetic field (H<~1 kOe) in both thin- plate (thickness<150 nm) and bulk forms.

17 pages, 4 figures

References in corpus (4)

• Theory of current-driven motion of Skyrmions and spirals in helical magnets
• Long wavelength helimagnetic order and skyrmion lattice phase in Cu2OSeO3
• Rotating skyrmion lattices by spin torques and field or temperature gradients
• Electric field-induced Skyrmion distortion and giant lattice rotation in the magnetoelectric insulator Cu2OSeO3

Cited by in corpus (20)

• Additive interfacial chiral interaction in multilayers for stabilization of small individual skyrmion at room temperature
• Skyrmions in Magnetic Multilayers
• Direct imaging of a zero-field target skyrmion and its polarity switch in a chiral magnetic nanodisk
• Hund's rule-driven Dzyaloshinskii-Moriya interaction at 3d-5d interfaces
• Néel-type skyrmion lattice in tetragonal polar magnet VOSe${}_2$O${}_5$
• Skyrmion formation in a bulk chiral magnet at zero magnetic field and above room temperature
• Symmetry breaking, slow relaxation dynamics, and topological defects at the field-induced helix reorientation in MnSi
• Spin-wave spectroscopy on Dzyaloshinskii-Moriya interaction in room-temperature chiral magnets hosting skyrmions
• Deciphering structural and magnetic disorder in the chiral skyrmion host materials Co${}_x$Zn${}_y$Mn${}_z$ ($x+y+z=20$)
• Reversible Vector Ratchets for Skyrmion Systems
• Element-specific soft X-ray spectroscopy, scattering and imaging studies of skyrmion-hosting compound Co${}_8$Zn${}_8$Mn${}_4$
• Reorientations, relaxations, metastabilities and multidomains of skyrmion lattices
• Observation of Topological Hall Effect and Signature of Room Temperature Antiskyrmions in Mn-Ni-Ga D2d Heusler magnets
• Positron spectroscopy of point defects in the skyrmion-lattice compound MnSi
• Exploring the origins of the Dzyalloshinski-Moria interaction in MnSi
• Measuring the Formation Energy Barrier of Skyrmions in Zinc Substituted Cu${}_2$OSeO${}_3$
• Orientation dependent current-induced motion of skyrmions with various topologies
• Imaging and manipulation of skyrmion lattice domains in Cu2OSeO3
• Spin excitations in the skymion host Cu2OSeO3
• Topological Hall effect in bulk ferromagnet Cr${}_2$Te${}_3$ embedded with black-phosphorus-like bismuth nanosheets