Bimodal growth mode of Fe/ cc(110) ; cc=(W,Mo) Application to the - - PowerPoint PPT Presentation

▶
bimodal growth mode of fe cc 110 cc w mo application to
SMART_READER_LITE
LIVE PREVIEW

Bimodal growth mode of Fe/ cc(110) ; cc=(W,Mo) Application to the - - PowerPoint PPT Presentation

Dec 23, 2022 215 likes •554 views

Bimodal growth mode of Fe/ cc(110) ; cc=(W,Mo) Application to the self-organization of thick stripes O.Fruchart, Laboratoire Louis Nel (CNRS), Grenoble I CCG1 4 Aug. 2 0 0 4 Laboratoire Laboratoire Louis Nel. Louis Nel.

slide-1
SLIDE 1

I CCG1 4 –

  • Aug. 2 0 0 4

Laboratoire Louis Néel. Laboratoire Laboratoire Louis Néel. Louis Néel.

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

Bimodal growth mode of Fe/ cc(110) ; cc=(W,Mo) Application to the self-organization of thick stripes

O.Fruchart,

Laboratoire Louis Néel (CNRS), Grenoble

slide-2
SLIDE 2

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.2

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Outline

Evidence for bim odal grow th Application to self-organized thick stripes Extend versatility of self-assem bly Discussion of results from the literature

slide-3
SLIDE 3

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.3

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Growth of Fe/ W-Mo(110) systems

Grow th processes

  • Motivation: model system for 2D magnetism

(no alloying, pseudomorphic, layer-by-layer)

  • Grow th:
  • Pseudomorphic 1st layer, then Stranski-Krastanov
  • Kinetic roughness along [ 001] at room temperature
  • Progressive increase of temperature for flat films
  • Dots at high temperature
  • Substrate: quanlitatively (if not quantitatively) similar results

for W(110) and Mo(110).

  • Pioneering: Gradmann82, Tikhov-Bauer90
  • Follow ing: Elm ers-Gradmann90, Albrecht-Gradmann93, Bethge95
  • Stripes: Hauschild-Gradmann98, Bode-Wiesendanger00

Self- organization

  • Step-decoration of vicinal surfaces: 0.5ML, 1.5ML.

Curie temperature < 300K Key references

slide-4
SLIDE 4

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.6

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe/ Mo(110) – the surface

Single crystalline Mo(110) surface, with atomic steps :

Mo[001] Mo[1-10] Mo[1-11]

Al2O3 +/- 0.1° Mo (110)//(11-20) 150nm-500nm

Buffer layer growth : O. Fruchart, S. Jaren, J. Rothm an, Appl. Surf. Sci. 1 3 5 , 2 1 8 ( 1 9 9 8 )

cc(110) surface :

STM- 600x600 nm STM- 750x750 nm

// [001] 150nm 45° from [001] 200nm

PULSED LASER DEPOSITION, UHV

cc(110)/Al2O3(11-20) cc=Mo, W, Nb, etc.

Target Nd:YAG Pulsed Laser

THE SURFACE

1 0 nm

Ex-situ AFM 10 x 10 µm

MBE versus PLD : J. .Shen et al., Surf. Sci. Rep., 5 2 , 1 6 3 ( 2 0 0 4 )

slide-5
SLIDE 5

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.9

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe/ Mo(110) – bimodal growth ?

AFM, 3µm x 2.8µm AFM, 3.6µm x 3.6µm

enom = 8 nm ~ 40ML

Mean coverage (nm) Volume per unit surface (nm)

2 4 6 8 2 4 6 8

0.7nm 8nm

50% Vol. 90% Vol. h=1.2nm 50% Vol. h=1.2nm 10% Vol.

enom = 0.7 nm ~ 3.5ML

3D 3D Flat Flat 3D Flat

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

Bimodal Stranski-Krastanov growth

Fe Mo(110) Ts = 700K

P.- O.Jubert et al. , JMMM 2 2 6 , 1 8 4 2 ( 2 0 0 1 ) P.- O.Jubert et al. , PRB6 4 , 1 1 5 4 1 9 ( 2 0 0 2 )

slide-6
SLIDE 6

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.10

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Self-assembly : shape of dots

γi γj hi hj

W ulff’s theorem

Free crystal

W ulff Kaishev’s theorem

γi hi

hint

Supported crystal (growth on surfaces)

No facets with high surface energy Truncated crystal

slide-7
SLIDE 7

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.11

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Self-assembly – more versatility

Based on Wulff’s construction

I nterface energy deduced from m easurem ents

Micron -size dots:

Includes interfacial dislocation energy

Effective interface energy

0.0 0.5 1.0 1.5 1 2 3

Mo w

Lateral ratio r=L/W

0.0 0.1 0.2 0.3 0.4 0.5

Interfacial energy (J.m

  • 2)

Vertical ratio η=H/W

2 int

J.m 15 . 65 . ) Mo Fe (

−

± = − E

2 int

J.m 1 . 15 . ) W Fe (

−

± = − E

slide-8
SLIDE 8

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.12

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe/ Mo(110) – metastable critical thickness

25°C growth + 450°C Annealing 2.5AL, 5 x 5 µm 3AL, 5 x 5 µm 3.75AL, 5 x 5 µm 5.75AL, 5 x 5 µm 6.5AL, 10 x 10 µm 7.25AL, 10 x 10 µm 8.25AL, 10 x 10 µm t<7AL:

7AL metastable patches

t>7AL:

patches are ‘sucked’

3D dots more stable

than 7AL patches.

  • Ex-situ AFM
slide-9
SLIDE 9

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.13

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe/ Mo(110) – why stripe nucleation along steps ?

~ 2.5AL ~ 3.25AL ~ 2AL

Fe films grown at 150°C STM, 600nm x 600nm

STM, 750nm x 750nm

Al2O3 Mo Fe

Step 1 : layer-by-layer grow th at 1 5 0 ° C Step 2 : annealing at 5 0 0 ° C -- > stripes along steps

  • O. Fruchart et al. , APL 8 4 , 1 3 3 5 ( 2 0 0 4 )
slide-10
SLIDE 10

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.14

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

1nm-thick stripes – orientation

3.5x3.5 µm 10x10 µm 5x5 µm

(Slightly too high temperature for this sample… )

7ML stripes (instead of 1-2ML usually) Tunable orientation To be optimized for better quality

Fe[ 1 - 1 0 ] Fe[ 0 0 1 ]

slide-11
SLIDE 11

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.15

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe(110) stripes – stripes with increased height Sapphire\ W ( 8 nm ) \ Fe( 1 5 0 ° C + 4 5 0 ° C annealing) Stripes for Fe/W(110) Increased height : 5.5nm (significant advancement compared with existing literature)

[ 1.8nm ]

Stripe = 4.0nm

[ 2.4nm ]

Stripe = 5.0nm

[ 1.2nm ]

Stripe height = 5.5nm

[ 3.0nm ]

Stripe height = 5.5nm

slide-12
SLIDE 12

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.16

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe(110) stripes – stripes remanence and coercivity at 300K

  • 100

100

  • 1.0
  • 0.5

0.0 0.5 1.0 100 K 200 K 300 K

M/Ms Applied field (mT)

H//[001]

  • 100

100

  • 1.0
  • 0.5

0.0 0.5 1.0

100 K 200 K 300 K

M/Ms Applied field (mT)

H//[1-10]

[001] [1-10] 10 µm

Sapphire \ W \ Fe(3nm) \ Mo

  • O. Fruchart et al. , APL 8 4 , 1 3 3 5 ( 2 0 0 4 )

Coercivity and rem anence at 3 0 0 K Coercivity and high remanence at 300K Weak temperature dependence

> behaves like a conventional material

slide-13
SLIDE 13

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.19

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Fe(110) stripes – other systems for thick stripes ?

  • S. Cherifi et al. , PRB 6 4 ( 2 0 0 1 ) 1 8 4 4 0 5

STM, 80x70 nm 3 ML Fe65Ni35 / Cu(111)-vic 1.2°

Grooves along steps

General phenomenon that may be exploited ?

slide-14
SLIDE 14

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.20

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Explaining the magical height Quantum confinem ent

Evidence for ‘magic’ heights have been reported for several syst ems: Pb/ Cu( 1 1 1 ) : 6,8,11,15,17,20 ML. R. Otero et al., PRB6 6 , 1 1 5 4 0 1 ( 2 0 0 2 ) Ag/ GaAs: A.R. Smith et al., Science 2 7 3 , 2 2 6 ( 1 9 9 6 ) Ag/ Si( 1 1 1 ) : L. Gavioli et al., Phys. Rev. Lett. 8 2 , 1 2 9 ( 1 9 9 9 )

  • L. Huang et al., Surf. Sci. 4 1 6 , L1 1 0 1 ( 1 9 9 8 )

Pb/ Si( 1 1 1 ) : V. Yeh et al., Phys. Rev. Lett. 8 5 , 5 1 5 8 ( 2 0 0 0 )

W . B. Su et al., Phys. Rev. Lett. 8 6 , 5 1 1 6 ( 2 0 0 1 )

Au/ Fe( 0 0 1 ) : 5ML, D. A. Luh et al., Science 2 9 2 , 1 1 3 1 ( 2 0 0 1 ) However, several magical heights would be expected…

Under investigation

slide-15
SLIDE 15

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.21

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Explaining the magical height

Possible explanation = elastic energy m inim ization com m ensurate / incom m ensurate transition of interface dislocation array at the ‘m agical’ thickness.

WETTING ( )

AL

INTERMEDIATE METASTABLE THICKNESS

DOT

3D

10Mo / 11Fe compressive stress 11Mo / 12Fe tensile stress

Transition of the interfacial dislocation netw ork

slide-16
SLIDE 16

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.22

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Pseudomorphic interfacial layer

Mo Fe Mo Fe. W

Control interface independently from lattice param eter

0.0 0.2 0.4 0.6 0.8 1.0

Epaisseur de W déposé 20 Å 12 16 8 4 7.2 9.0 MC 5.4 3.6 1.8

Recuit aucun 200 400 600 e(-t/t0) t0=0.90 nm

Intensité normalisé du signal de Mo (u.a)

Quantitative Auger spectroscopy 2 5 ° C grow th + 800° C Annealing

No interface intermixing Atomically-flat surface

STM (800x800 nm)

slide-17
SLIDE 17

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.23

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Solid solutions

W Mo

‘m ixture’ ~ Solid solution

Continuous control of lattice param eter

  • Continuously variable buffer layer lattice parameter
  • Atomically flat surface; atomic steps array

≤ 10nm Opposite w edges Pseudom orphic W ( or Mo) 3.147 Å 3.165 Å

slide-18
SLIDE 18

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.24

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Solid solutions (X-rays)

In-plane lattice parameter from aMo= 3.147 Å to aW = 3.165 Å

Continuous control of lattice param eter

slide-19
SLIDE 19

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.25

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Interface – effect on stripes

Height : 4.5nm Average thickness 1nm 2.5nm Chem ical interface Fe / W ( < 1 nm ) / Mo Fe / Mo

Sapphire\ Mo( 8 nm ) \ interface \ Fe( 1 5 0 ° C, 4 5 0 ° C annealing)

10 µm Height : bim odal 1.5/ 4nm

slide-20
SLIDE 20

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.26

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Parameter mismatch – effect on stripes

x

Continuous control of lattice param eter

Dram atic effect on stripe grow th

slide-21
SLIDE 21

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.27

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Parameter mismatch – effect on stripes (2)

0.0 0.2 0.4 0.6 0.8 1.0 1 2 3 4 5 6 7 8

W content (%) Stripes' height (nm)

Continuous control of lattice param eter

Significant effect on stripe height

  • Hypothesis of commensurate/incommensurate

transition needs to be confirmed

slide-22
SLIDE 22

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.28

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Flat patches at very high temperature Continuous control of lattice param eter

Sim ilar effect on patches of m etastables height Fe( 1 1 0 ) / W xMo1- x at 8 0 0 ° C 3 ML Fe/ Mo( 1 1 0 ) 6 ML Fe/ Mo( 1 1 0 )

  • Only patches of metastable height form at very high temperature

(no 3D dots)

slide-23
SLIDE 23

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.29

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Flat patches at very high temperature (2) Continuous control of lattice param eter

Sim ilar effect on patches of m etastables height Fe( 1 1 0 ) / W ( 3 ML) / W xMo1- x at 8 0 0 ° C 1.0 0.8 0.6 0.4 0.2 0.0 2.0 3.0 4.0 5.0 6.0 Mo content (%) Height of flat patches (nm)

0.0 0.2 0.4 0.6 0.8 1.0 1 2 3 4 5 6 7 8

W content (%) Stripes' height (nm)

Reminder: Height of stripes Same height for ‘thick’ stripes (moderate temp. Plus annealing) and flat patches (high temp. Growth)

Thermodynamic property – Origin to be confirmed

slide-24
SLIDE 24

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.30

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Lattice mismatch on 3D dots

Differences: size, shape, density, aspect ratios

Lattice param eter : w eak effect on dots

slide-25
SLIDE 25

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.31

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Lattice mismatch on 3D dots (2)

Interface Mo Interface Mo Interface W Interface W

W eak lattice param eter change : no effect on dots

I n- plane aspect ratio Vertical aspect ratio

slide-26
SLIDE 26

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.33

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Diagram of growth modes

[001]

Layer-by-layer growth (PLD) 1ML islands 3D dots + flat patches Flat patches only Step-flow decoration Nanostripes Layer-by-layer (PLD) Kinetic roughness

300K 500K 700K 900K

1PA 2PA 3PA 4PA >6PA

Deposition temperature (K)

Yet non-explored

Atomic monolayers (MLs)

T =700K, [2ML,6ML] h=6ML

r

Θ T >400K, >6ML

r

Θ Ilots biseautés ~1nm t Ilots compacts >30nm t ~3.5ML, 5 m µ

[-110] [001] (110)

slide-27
SLIDE 27

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.34

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Discussion of data from the literature

  • A. W achow iak et al., Science 2 9 8 , 5 7 7 ( 2 0 0 2 )

Deposition at RT on W (8-10ML) Annealing at 800± 1 0 0 K Stepped substrate Width= 215nm Height= 8nm; r= 0.037 Length= 471nm; η= 1.93 Literature Our data Consistent with 3D dots W W Deposition at 7 7 5 ± 50K Essentially flat substrate Height ratio r= 0.07 Length ratio η= 2.3

slide-28
SLIDE 28

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.35

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Discussion of data from the literature

  • D. Sander, Rep. Prog. Phys. 6 2 , 8 0 9 ( 1 9 9 9 )

[ see also Schm idt, private com m .]

Deposition at 1 0 0 0 K on W, or deposition at RT and annealed 7 0 0 - 1 0 0 0 K Thickness= 10-20nm (private comm.) Wires do not follow atomic steps Literature Our data W W Deposition at 5 0 0 K on W, annealed 775± 5 0 K Thickness= 5.5nm± 0.5nm Wires follow atomic steps (1 per step) Deposition at the layer-by-layer growth temperature is essential to keep the information about the atomic steps

slide-29
SLIDE 29

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.36

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Discussion of data from the literature

I . V. Shvets et al., cond- m at/ 0405148 ( 2004)

500x350nm Deposition at ~ 4 9 5 K on Mo Stepped substrate

  • J. Malzbender et al., Surf. Sci. 4 1 4 , 1 8 7 ( 1 9 9 8 )

Deposition at 6 0 0 K on Mo (2.9ML) Largest thickness= 10ML

[ See also: Bethge et al., Koehler, Surf. Sci 3 3 1 / 3 3 3 ( 1 9 9 5 ) 8 7 8 .]

  • S. Murphy et al., PRB6 6 , 1 9 5 4 1 7 ( 2 0 0 2 )

500x500nm (2.4ML) Literature Mo Consistent with flat dots

Onset of 3D growth not reached yet ?

slide-30
SLIDE 30

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.37

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Discussion of data from the literature

  • R. Röhlsberger et al., PRB6 7 , 2 4 5 4 1 2 ( 2 0 0 3 )

Deposition at RT on W (5ML) Annealing at 700K Width= 195nm Height= 3.7± 0.8nm; r= 0.019 Length= distributed (Cf our experiments)

  • D. Sander, Rep. Prog. Phys. 6 2 , 8 0 9 ( 1 9 9 9 )

Deposition at 1000K on W, or deposition at RT and annealed 700-1000K Largest thickness= 10ML In principle, same parameters used.

Influence of the step density?

Literature W

slide-31
SLIDE 31

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.38

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Conclusion

  • Evidence for bimodal island growth
  • Attempt to separate interfacial and mismatch effects
  • Tunability of the geometry of nanostructures:

* aspect ratios of 3D dots * height of the stripes

Grow th of Fe( 1 1 0 ) revisited

  • Micromagnetism in 3D dots
  • Self-organized stripes magnetically

functional at 300K

  • Domain wall in constriction (nano-ties)
  • 100

100

100 K 200 K 300 K

Applied field (mT)

Self-assem bly for m agnetism

(see T02-1079, Friday) 2 µm New self-assembled systems Ex: nano-tie-knots

slide-32
SLIDE 32

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.39

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Collaborators

Laboratoire Louis Néel (CNRS), Grenoble (France) P.-O. Jubert (PhD), M. Eleoui (PhD), F. Cheynis (Master student), O.Fruchart, C. Meyer

Technical support: V. Santonacci, Ph. David, A. Liénard,

  • S. Biston, S. Pellé

Growth and magnetism X-ray diffraction

Crystallography laboratory - Grenoble (France)

  • L. Ortega
slide-33
SLIDE 33

Olivier Fruchart – ICCG14 –

  • Aug. 2004

– p.40

Laboratoire Louis Néel Laboratoire Laboratoire Louis Néel Louis Néel

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

Advertisement…

Special issue on Self- organization at surfaces

Compte-Rendus Physique (C. R. Phys.), (~ Jan.2005),

  • rganized by the French Academy of Sciences

9 authors, ~ 100 pages (english) Covers metals, semiconductors, growth, characterization, physical properties I nformation soon available on: http: / / lab-neel.grenoble.cnrs.fr/ pageperso/ fruche/ [ detailed content, direct ordering (~ 15€), etc.]