TY - JOUR
T1 - Quantifying chiral exchange interaction for Néel-type skyrmions via Lorentz transmission electron microscopy
AU - Jiang, Wanjun
AU - Zhang, Sheng
AU - Wang, Xiao
AU - Phatak, Charudatta
AU - Wang, Qiang
AU - Zhang, Wei
AU - Jungfleisch, Matthias Benjamin
AU - Pearson, John E.
AU - Liu, Yizhou
AU - Zang, Jiadong
AU - Cheng, Xuemei
AU - Petford-Long, Amanda
AU - Hoffmann, Axel
AU - Te Velthuis, Suzanne G.E.
N1 - Funding Information:
Work performed at Tsinghua, including data analysis and manuscript preparation, was supported by the National Key R&D Program of China under Contracts No. 2017YFA0206200 and No. 2016YFA0302300, NSF of China under Contracts No. 11774194, No. 51831005, and No. 11861131008, and the Beijing Advanced Innovation Center for Future Chip (ICFC). Work carried out at Argonne National Laboratory, including all experimental aspects, data analysis, and manuscript preparation, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division. Work at Bryn Mawr College was supported by NSF CAREER Award No. 1053854 and NSF DMR Grant No. 1708790. Micromagnetic simulation carried out by the University of New Hampshire was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES) under Award No. DE-SC0016424. Use of the Center for Nanoscale Materials, an Office of Science user facility, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
PY - 2019/3/4
Y1 - 2019/3/4
N2 - Magnetic skyrmions are topological spin textures that have been observed in bulk magnets and magnetic multilayers. For bulk magnetic materials, their noncollinear spin profiles have often been studied by using Lorentz transmission electron microscopy (TEM). We experimentally utilized Lorentz TEM imaging to study an inversion asymmetric [Pt(1.5nm)/Co(1nm)/W(1nm)]8 heterostructure that exhibits Néel-type skyrmions at zero field. By tracking the evolution of skyrmion diameters as a function of magnetic fields, we determined the strength of the interfacial Dzyaloshinskii-Moriya interaction (DMI). Our results suggest that in situ Lorentz TEM imaging combined with simulations can provide valuable quantitative information about the interfacial DMI strengths, which can be helpful for optimizing skyrmion materials. Furthermore, we show that in theory, Lorentz TEM can identify the spin chirality of Néel-type skyrmions, although an experimental verification is challenging due to the relatively low signal-to-noise ratio.
AB - Magnetic skyrmions are topological spin textures that have been observed in bulk magnets and magnetic multilayers. For bulk magnetic materials, their noncollinear spin profiles have often been studied by using Lorentz transmission electron microscopy (TEM). We experimentally utilized Lorentz TEM imaging to study an inversion asymmetric [Pt(1.5nm)/Co(1nm)/W(1nm)]8 heterostructure that exhibits Néel-type skyrmions at zero field. By tracking the evolution of skyrmion diameters as a function of magnetic fields, we determined the strength of the interfacial Dzyaloshinskii-Moriya interaction (DMI). Our results suggest that in situ Lorentz TEM imaging combined with simulations can provide valuable quantitative information about the interfacial DMI strengths, which can be helpful for optimizing skyrmion materials. Furthermore, we show that in theory, Lorentz TEM can identify the spin chirality of Néel-type skyrmions, although an experimental verification is challenging due to the relatively low signal-to-noise ratio.
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U2 - 10.1103/PhysRevB.99.104402
DO - 10.1103/PhysRevB.99.104402
M3 - Article
AN - SCOPUS:85062715435
VL - 99
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 0163-1829
IS - 10
M1 - 104402
ER -