AVS 65th International Symposium & Exhibition
    Magnetic Interfaces and Nanostructures Division Thursday Sessions
       Session MI+2D-ThM

Invited Paper MI+2D-ThM5
New Insights into Nanomagnetism by Low-temperature Spin-polarized Scanning Tunneling Microscopy

Thursday, October 25, 2018, 9:20 am, Room 203A

Session: Magnetism at the Nanoscale
Presenter: Dirk Sander, Max Planck Institute of Microstructure Physics, Germany
Correspondent: Click to Email

Spin-polarized scanning tunneling microscopy at low temperature (8 K) and in high magnetic fields (6 T) is a powerful technique to investigate magnetic properties of individual nanoscale objects ranging in size form single atoms to several thousand atoms [1]. I focus on the magnetization reversal [2] and the spin-dependent electronic properties of bilayer Co [3], Fe-decorated Co and Fe islands on Cu(111). We find a novel noncollinear, helical magnetic order in the Fe islands, which is identified by a magnetic stripe contrast with a period of 1.28 nm [4,5] in bilayer islands. The periodicity increases to 2.2 nm in three-layer thick Fe islands [6]. The high spatial resolution of the spin-polarized scanning tunneling spectroscopy in combination with theory reveals the significance of structural and electronic relaxation [7] for the magnetic anisotropy, for subtle balances between ferromagnetic and antiferromagnetic exchange interaction, and for spin-dependent transport properties [8] of individual, single nanostructures.

[1] H. Oka, O. Brovko, M. Corbetta, V. Stepanyuk, D. Sander, J. Kirschner,

Rev. Mod. Phys. 86 (2014), 1127.

[2] S. Ouazi, G. Rodary, S. Wedekind, H. Oka, D. Sander, J. Kirschner,

Phys. Rev. Lett. 108 (2012) 107206.

[3] H. Oka, P. Ignatiev, S. Wedekind, G. Rodary, L. Niebergall, V. Stepanyuk, D. Sander, J. Kirschner, Science 327 (2010) 843.

[4] S. Phark, J. Fischer, M. Corbetta, D. Sander, K. Nakamura, J. Kirschner,

Nat. Commun. 5 (2014) 5183.

[5] J. Fischer, L. Sandtratskii, S. Phark, S. Ouazi, A. Pasa, D. Sander, St. Parkin

Nat. Commun. 7 (2016) 13000.

[6] J. Fischer, L. Sandratskii, S. Phark, D. Sander, St. Parkin,

Phys. Rev. B 96 (2017) 140407(R).

[7] O. Brovko, D. Bazhanov, H. Meyerheim, D. Sander, V. Stepanyuk, J. Kirschner,

Surface Science Reports 69 (2014) 159.

[8] H. Oka, K. Tao, S. Wedekind, G. Rodary, V. Stepanyuk, D. Sander, J. Kirschner,

Phys. Rev. Lett. 107 (2011) 187201.