Berlin 2005 – scientific programme
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MA: Magnetismus
MA 24: Oberfl
ächenmagnetismus
MA 24.8: Talk
Tuesday, March 8, 2005, 12:15–12:30, TU A060
Growth and electronic properties of thick films and pyramidal islands of Dy/W(110) studied by STM/STS — •Luis Berbil-Bautista, Stefan Krause, Torben Hänke, Matthias Bode, and Roland Wiesendanger — Institut of Applied Physics, University of Hamburg, Jungiusstraße 11, Germany
The magnetic structure of bulk Dysprosium (Dy) exhibits two phase transitions with decreasing temperature T: from paramagnetic to helimagnetic at TN = 178 K and from helimagnetic to ferromagnetic at TC = 85 K [1]. The helimagnetic phase is particularly interesting as the turn angle between two adjacent basal (0001) planes Dy varies between 43∘ at TN and 26∘ at TC [2].
The magnetic structure of the Dy(0001) surface is basically unknown. Since it is almost impossible to clean Dy bulk crystals we have studied the growth and electronic structure of Dy films on W(110) by STM and STS, respectively. In agreement with Wegner et al. [3] our tunneling spectra are dominated by a double-peak structure which originates from an exchange-split d-derived surface state. The exchange splitting amounts to 500 meV at T = 20 K.
By an appropriate variation of the substrate temperature during growth stepped-pyramidal islands were prepared. These islands may be suitable for an investigation of the surface helimagnetic turn angle as numerous different atomic planes are exposed to the surface.
[1] D.R. Behrendt et al., Phys. Rev. 109, 1544 (1958).
[2] M.K. Wilkinson et al., J. Appl. Phys. 32, 48S (1961).
[3] D. Wegner et al., to be published.