Domain dynamics in Co/Pt/Co/Pt/Co/IrMn M. Czapkiewicz

Domain dynamics in Co/Pt/Co/Pt/Co/IrMn

M. Czapkiewicz

New domain nucleation:N(t)=N0(1-exp(-Rt))

Fatuzzo: cylindric domains nucleation and growth B(t)=

exp(-2k2(1-(1 -(Rt+1/k) +0.5(Rt+1/k)2 –e-Rt(1-1/k) –0.5k2(1-Rt)))

where k=v/Rr,

v i R increase with z H, kconst R=R0exp[-(WN-2HMSVN)/kBT]

v=v0exp[-(WP-2HMSVP)/kBT]

k: real time

k: reduced time

0 5 10 15-0.2

0.0

0.2

0.4

0.6

0.8

1.0

1.2

- 20 mT- 19.0 mT- 18.7 mT- 18.2 mT- 18.1 mT- 17.5 mT- 17.1 mT- 16.2 mT- 15.6 mT- 15.2 mT- 14.2 mT- 13.3 mT

B [n

orm

aliz

ed

Time [sec]

-100% to -10.5%

0 1 2 3 4 50.0

0.2

0.4

0.6

0.8

1.0

-100% to -10.5%

- 20 mT- 19.0 mT- 18.7 mT- 18.2 mT- 18.1 mT- 17.5 mT- 17.1 mT- 16.2 mT- 15.6 mT- 15.2 mT- 14.2 mT- 13.3 mT

B(t

r)

t/t50

#26 backward

#26 forward

0 10 20 30 40 50 60 700.0

0.2

0.4

0.6

0.8

1.0

- 35.6 mT - 36.2 mT - 36.9 mT - 37.6 mT - 38.3 mT - 39.6 mT

B [N

orm

aliz

ed]

Time [sec]

+ 100% to -21%

0 2 40.0

0.2

0.4

0.6

0.8

1.0

+ 100% to -21%

- 35.6 mT - 36.2 mT - 36.9 mT - 37.6 mT - 38.3 mT - 39.6 mT

B(t

r)

t/t50

#26 backward

#26 forward

#26 real time

#31 forward – without dead time correction

0.0 0.2 0.4 0.6 0.8 1.0 1.2

0.0

0.2

0.4

0.6

0.8

1.0

47,07 mT 35,85 mT 33,92 mT 32,13 mT 30,35 mT 28,56 mT 26,6 mT 24,74 mT 22,89 mT 20,98 mT 18,97 mT 17,06 mT 15,2 mT 13,3 mT 11,4 mT 9,49 mT 7,70 mT 5,79 mT 3,85 mT

Ur [

No

rma

lize

d]

Time [s]

Sample # 31

0.00 0.25 0.50 0.75 1.00 1.25 1.50

0.0

0.2

0.4

0.6

0.8

1.0

47,07 mT 35,85 mT 33,92 mT 32,13 mT 30,35 mT 28,56 mT 26,6 mT 24,74 mT 22,89 mT 20,98 mT 18,97 mT 17,06 mT 15,2 mT 13,3 mT 11,4 mT 9,49 mT 7,70 mT 5,79 mT 3,85 mT

Ur

[No

rma

lize

d]

t/t50

Sample #31

#31 forward – dead time correction

#31 forward – fit after dead time correction

Kerr video: for H=21.1mT v=10m/s

#31 forward – before dead time correction – impossible to fit

#31 backward – fit after dead time correction

Kerr video: for H=7.8mT v=50m/s