Croissance et proprits magntiques de rseaux planaires auto-organiss - - PowerPoint PPT Presentation

▶
croissance et propri t s magn tiques de r seaux planaires
SMART_READER_LITE
LIVE PREVIEW

Croissance et proprits magntiques de rseaux planaires auto-organiss - - PowerPoint PPT Presentation

Oct 09, 2023 237 likes •403 views

Croissance et proprits magntiques de rseaux planaires auto-organiss de nanofils de Fer B. Borca, O.Fruchart, M. Hasegaw a, C. Meyer Laboratoire Louis Nel (CNRS-UJF-INPG) Grenoble Olivier Fruchart JMC10 Toulouse Aug.

slide-1
SLIDE 1

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006

Croissance et propriétés magnétiques de réseaux planaires auto-organisés de nanofils de Fer

  • B. Borca, O.Fruchart, M. Hasegaw a, C. Meyer

Laboratoire Louis Néel (CNRS-UJF-INPG) Grenoble

slide-2
SLIDE 2

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.2

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

INTRODUCTION – Context Stripes and wires

  • P. Gam bardella et al., Science 3 0 0 , 1 1 3 0 ( 2 0 0 3 )
  • P. Gam bardella et al., Nature 4 1 6 , 3 0 1 ( 2 0 0 2 )
  • A. Dallm eyer et al., PRB 6 1 ( 8 ) , R5 1 5 3 ( 2 0 0 0 )

Co/Pt(997)

350 x 350 nm

D.D. Cham bliss et al., PRL 6 6 , 1 7 2 1 ( 1 9 9 1 ) B.Voigtlander et al., PRB 4 4 , 1 0 3 5 4 ( 1 9 9 1 )

  • J. P. Bucher et coll.; S. Rousset et coll.;
  • O. Fruchart et coll.

Dots Co/Au(111)

Self-organization at surfaces : 2D regular arrays of similar nanostructures

Cheaper and beyond lithography Fundamental research: weak distributions > reliable analysis Applications? lack of versatility (tunability; use no vicinal nor reconstructed surface) What for?

slide-3
SLIDE 3

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.3

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

INTRODUCTION – Self-organization without reconstructions or steps Stripes and wires Dots

Demonstrated path: ion etching

  • T. Aste and U. Valbusa, New J. Phys. 7 ,

1 2 2 ( 2 0 0 5 )

Ag

Etched magnetic films (with or without mask) Magnetic wires

GaSb(001)

  • F. Facsko et al., Science 2 8 5 , 1 5 5 1 ( 1 9 9 9 )

200nm

slide-4
SLIDE 4

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.4

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

INTRODUCTION – Self-organization without reconstructions or steps

  • M. Albrecht et al., Surf. Sci. 2 9 4 , 1 ( 1 9 9 3 )

Fe(110) homoepitaxy

Hills and grooves by kinetically-limited growth on bcc(110) LEED

W(110) homoepitaxy

STM

  • U. Köhler et al., Surf. Sci. 4 5 4 -4 5 6 , 6 7 6 ( 2 0 0 0 )

Simulation

Any use for magnetic wires?

slide-5
SLIDE 5

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.5

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – UHV-PLD chambers

Pulsed Laser Deposition (DLP) in UHV

cc(110)/Al2O3(11-20) cc=Mo, W, Nb, etc. Target Nd:YAG pulsed laser Substrate Mask

Analysis

  • RHEED (Reflection High-Energy

Electron Diffraction)

  • STM (Scanning Tunneling Microscopy)
  • AES (Auger Electron Spectroscopy)

Wedges

slide-6
SLIDE 6

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.6

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Trenches: Mo (1/2)

Al2O3 Mo

Buffer layers for trenches

Deposition of bcc refractory metals along (110) 200nm 50nm 50nm RT deposition Annealed 800°C RT-150°C deposition Al2O3 Mo Al2O3 Mo Mo

Uniaxial array of trenches (epitaxial) Long-range orientational order

[001] [1-10] Mo

slide-7
SLIDE 7

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.7

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Trenches: Mo (2/2)

200nm 50nm

(110) [-110] [001] (110) [001] [1-10]

RHEED

Mo, RT, annealed Mo, RT [001] [1-10]

STM

8nm

slide-8
SLIDE 8

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.8

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Trenches: atomic structure

[1-10] [1-10] [001] (110) (110) (00-1)

Lateral period ~5 nm Depth of trenches: 0.6-1 nm Figures for Mo

Atomic structure of the facets

Facets of type {210} θ=18.43°

slide-9
SLIDE 9

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.9

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Trenches: W (1/2)

W deposited at 150°C 9 9 9

Al2O3

W W

Process for W

Mo 20nm

STM RHEED

Order is improved with W

Lateral period ~5.5 nm Satellite streaks > Lateral period ~5.5 nm

(110) [-110] [001]

slide-10
SLIDE 10

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.10

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

RHEED

GROWTH – Trenches: W (2/2)

STM

W deposited under decreasing temperature: 550°C 150°C

5 10 15 20 25 30 5 10 15 20 Angle of facets (°) Thickness (Å)

Well-defined facets {210} is the limiting facet [contrary to statement of Köhler et al. On small trenches, {310} (2000)]

20nm

Period ~ 10-12 nm Depth ~ 2-3 nm

>>> RHEED video

slide-11
SLIDE 11

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.11

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Fe (1/2)

5 10 15 20 25 30 1 2 3 4 5 Cross-section (nm) Distance (across wires)

1.7ML Fe 1.5ML Fe 1.2ML Fe 1ML Fe 0.8ML Fe 0.5ML Fe W

[001] Fe - 1.8 ML Fe – 1 ML Fe - 2.4 ML Fe - 1.5 ML

150nm x 150nm

Fe/W(110) with small period (5nm) at 150°C

Layer-by-layer growth Forms a smooth surface

slide-12
SLIDE 12

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.12

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

GROWTH – Fe (2/2)

Residual corrugation across the trenches Zoology of misfit dislocations

Some details about continuous films

slide-13
SLIDE 13

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.13

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

Structure

Magnetism – Mo/Fe/W

2.5ML Fe/W(110) with large period (12nm) at 150°C W Mo Fe

50 100 150 200 250 300 1 2 3 4

FC ZFC Applied field 10 mT Moment (A.m

2 x 10

  • 9)

Temperature (K)

  • 400
  • 200

200 400

  • 1.0
  • 0.5

0.0 0.5 1.0 H//[001] M/MS B (mT)

4K 25K 50K 100K

Magnetism

Capping for SQUID measurements

Easy axis along in-plane [001] Mean blocking temperature 100K Fe stripes at the bottom of the trenches

slide-14
SLIDE 14

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.14

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

Magnetism – Mo/Fe/Mo/W

W Mo Fe

  • 400
  • 200

200 400

  • 1.0
  • 0.5

0.0 0.5 1.0 H//[001] M/MS B (mT)

4K 25K 50K 100K 50 100 150 200 250 300 1 2 3 4

FC ZFC Applied field 10 mT Moment (A.m

2 x 10

  • 9)

Temperature (K)

  • 400
  • 200

200 400

  • 1

1 H//[001] M/MS H (mT)

10K 25K 50K 100K

50 100 150 200 250 300 2 4 6 8

Applied field 10 mT

FC ZFC

Moment (A.m

2 x 10

  • 9)

Temperature (K)

Mo/Fe/W

W Mo Fe

Mo/Fe/Mo/W

Fe/Mo surface anisotropy along [001] > Anisotropy increased Mean blocking temperature 175K

slide-15
SLIDE 15

Olivier Fruchart – JMC10 – Toulouse – Aug. 31st, 2006 – p.15

Laboratoire Louis Néel, Grenoble, France. Laboratoire Laboratoire Louis N Louis Né éel, Grenoble el, Grenoble, France , France. .

http:/ / lab-neel.grenoble.cnrs.fr/ them es/ couches/ ext/ slides/ http:/ / http:/ / lab lab-

  • neel.grenoble.cnrs.fr

neel.grenoble.cnrs.fr / / them es them es/ couches/ / couches/ ext ext / / slides slides/ /

Current focus

Q.Xie et al., PRL 7 5 ( 1 3 ) , 2 5 4 2 ( 1 9 9 5 )

Fabrication of multilayers

>>> RHEED Movie (Step: W) (Widespread for semiconductor QDs)

Unusual (not demonstrated?) for metals What becomes of strain, dislocations etc? Influence on magnetic anisotropy? Futuristic: trend of magnetic recording towards 3D (Cf S.S.P. Parkin, R. Cowburn) What for?

Engineer further magnetic anisotropy

Blocking temperature above 300K Get perpendicular anisotropy What for?

By what means?

  • Magnetic material
  • Capping material
  • Etc.