Magnetic Domains and Domain Walls Bitter-Technique (ferromagnetic - - PowerPoint PPT Presentation

magnetic domains and domain walls bitter technique
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Magnetic Domains and Domain Walls Bitter-Technique (ferromagnetic - - PowerPoint PPT Presentation

Magnetic Domains and Domain Walls Bitter-Technique (ferromagnetic colloids on surfaces) Stress induced domains in NiFe single crystal Magneto-optics Magneto-optical Kerr Effect Magneto-optical Kerr Effect Kerr microscopes Domains in Fe


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SLIDE 1

Magnetic Domains and Domain Walls

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SLIDE 2

Bitter-Technique (ferromagnetic colloids on surfaces) Stress induced domains in NiFe single crystal

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SLIDE 3

Magneto-optics Magneto-optical Kerr Effect

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SLIDE 4

Magneto-optical Kerr Effect

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SLIDE 5

Kerr microscopes

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SLIDE 6

Domains in Fe single crystal

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SLIDE 7

Transmission electron microscopy Lorentz microscopy

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SLIDE 8

Scanning electron microscopy with polarization analysis (SEMPA) Co single crystal (0001) SiFe single crystal

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SLIDE 9

Magnetic Force Microscopy Image: Border of a 30 µm wide bit track of 300 kfrpi (89 nm bit length)

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SLIDE 10
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SLIDE 11
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SLIDE 12

Electrons

Photo electron emission microscopy

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SLIDE 13

Excited oscillation modes

H

h I

1 2

H

h h I

1 2

I

1 2

AXMCD ~ M. ~ cos

16x32 µm2 10 nm Py/Cu

PhD-thesis of A. Krasyuk

Oscillating field , 1GHz, 0.2mT

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SLIDE 14

E ρ E ρ Tip Sample e- E ρ E ρ Tip Sample

antiparallel

SP-STM and magnetic contrast

parallel ) M , M ( cos ) eU ( m m ) eU ( n n ) eU ( n ) ( n ) eU ( n ) ( n ) U ( dU dI

S T S T S T S T S T

       

   

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SLIDE 15

W(110) Au(111)

Co

W(110) Au(111)

Co

  • T. Duden and E. Bauer,
  • M. R. S. Proc.,287 (1997).

W(110) Au Co

W tips -

flashing 2000 K evaporation - RT

10 ML Au 4 – 16 ML Co

[110]

Tip and sample preparation

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SLIDE 16

Out-of-plane magnetic contrast

100 nm

Fe Fe Mo Fe Fe Mo

100 nm

dI dU

__

dI dU

__ 4 ML Co/Au/W

[110] _ [001]

100 nm T = 5 K I = 1.5 nA U = 0.3V T = 5 K I = 1.5 nA U = 0.4V

(500  500) nm2 (500  500) nm2

Mo(110) Fe

height [Å] lateral displacement [nm]

Fe Mo(110)

height [Å] lateral displacement [nm]

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SLIDE 17

40nm

2 4 6 8 10 12 14

  • 50

50 100 150

X[nm] Z[mV]

1.2±0.2 nm

14nm

40nm

Domain wall width in the ML Fe nanowires

dI dU

__

dI dU

__ 4 ML Co/Au/W Fe Fe

Mo

T = 5 K I = 1.5 nA U = 1 V

(200  200) nm2 (70  70) nm2

Topography

] 001 [ ] 1 1 [

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SLIDE 18

Domain wall Width: wML = 6 Å Energy: eML=15.2 meV/atom row

Domain wall width in Fe on W(110)

Exchange stiffness A = 3.6 pJ/m (8.2 meV/atom) Anisotropy constant K = 41 MJ/m3 (4.0 meV/atom)

  • M. Pratzer, H.J. Elmers, M. Bode, O. Pietzsch,
  • A. Kubetzka, and R. Wiesendanger, Phys. Rev.
  • Lett. 87, 127201 (2001).
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SLIDE 19
  • A. Hubert and R. Schäfer

Springer 1998