Spin orbit torque switching of Gd (Fe90Co10 100-x alloys...Spin torque on a ferrimagnet Niklas...
15
Spin orbit torque switching of Gd x (Fe 90 Co 10 ) 100-x alloys Niklas Roschewsky , Suraj Cheema, Frances Hellman, Sayeef Salahuddin University of California – Berkeley Tomoya Matsumura, Takeshi Kato, Satoshi Iwata Nagoya University Furo-cho - Chikusa-ku
Transcript of Spin orbit torque switching of Gd (Fe90Co10 100-x alloys...Spin torque on a ferrimagnet Niklas...
-
Spin orbit torque switching of Gdx(Fe90Co10)100-x alloys
Niklas Roschewsky, Suraj Cheema, Frances Hellman, Sayeef Salahuddin
University of California – Berkeley
Tomoya Matsumura, Takeshi Kato, Satoshi Iwata
Nagoya University Furo-cho - Chikusa-ku
-
Spin torque on a ferrimagnet
Niklas Roschewsky 2
RE
TM
16 18 20 22 24 26 28 300.0
0.2
0.4
0.6
0.8
1.0
m (
no
rma
lize
d)
composition x (%)
Compensation:
x = 23.4
m(Gd)=7.2 B/atom
m(FeCo)=2.2 B/atom
-
Samples under investigation
Niklas Roschewsky 3
Transition metal (TM) rich Rare earth (RE) rich
-
Experimental setup
Niklas Roschewsky 4
-
Anomalous Hall effect
Niklas Roschewsky 5
-1000 -500 0 500 1000-15
-10
-5
0
5
10
15
M (
em
u)
B (mT)
Gd21
(Fe90
Co10
)79
Gd28
(Fe90
Co10
)72
-20 -10 0 10 20-3.0
-1.5
0.0
1.5
3.0
Gd21
(Fe90
Co10
)79
Gd28
(Fe90
Co10
)72
RA
HE (
)
B (mT)
j = 0.003107 A/cm
2
-20 -10 0 10 20-3.0
-1.5
0.0
1.5
3.0
Gd21
(Fe90
Co10
)79
Gd28
(Fe90
Co10
)72
RA
HE (
)
B (mT)
j = 0.003107 A/cm
2
-20 -10 0 10 20-3.0
-1.5
0.0
1.5
3.0
Gd21
(Fe90
Co10
)79
Gd28
(Fe90
Co10
)72
RA
HE (
)
B (mT)
j = 0.003107 A/cm
2
AHE follows sign of mz(TM)
-
Current switching of the magnetization
Niklas Roschewsky 6
-1.4 -0.7 0.0 0.7 1.4-2
-1
0
1
2 = 200 s
RA
HE (
)
j (107 A/cm
2)
BIP
|| j BIP
= 45 mT
Gd21
(Fe90
Co10
)79
-1.4 -0.7 0.0 0.7 1.4-2
-1
0
1
2
RA
HE (
)j (10
7 A/cm
2)
Gd28
(Fe90
Co10
)72
BIP
= 45 mTBIP || j
= 200 s
AHE follows sign of mz(Total)
-
Harmonic measurement of Beff
Niklas Roschewsky 7
-500 -250 0 250 500-2.50
-1.25
0.00
1.25
2.50
B (mT)
R (
)
BIP
|| j-20
-10
0
10
20
j = 0.27107 A/cm
2
Gd21
(Fe90
Co10
)79
R (
m
)
-500 -250 0 250 500-2
-1
0
1
2
B (mT)R
(
)
-50
-25
0
25
50
R (
m
)
j = 0.27107 A/cm
2 BIP
j
Gd28
(Fe90
Co10
)72
-
Harmonic measurement of Beff
Niklas Roschewsky 8
-500 -250 0 250 500-2
-1
0
1
2
B (mT)R
(
)
-50
-25
0
25
50
R (
m
)
j = 0.27107 A/cm
2 BIP
j
Gd28
(Fe90
Co10
)72
-500 -250 0 250 500-2.50
-1.25
0.00
1.25
2.50Gd
21(Fe
90Co
10)79
BIP
j
B (mT)
R (
)
j = 0.27107 A/cm
2
-20
-10
0
10
20
R (
m
)
-
Harmonic measurement of Beff
Niklas Roschewsky 9
-60 -40 -20 0 20 40 60-1.94
-1.92
-1.90
-1.88
-1.86
B (mT)
R (
)
-0.4
-0.2
0.0
0.2
0.4
2
6
2
2
)(1007.92
mTH
V
Gd21
(Fe90
Co10
)79
R (
m
)
Damping like torque
B || I
I = 8 mA
up-sweep
mTH
V
62 1081.5
Hayashi et al., Phys. Rev. B 89, 144425 (2014).
-
Effective fields in Gdx(Fe90Co10)100-x
Niklas Roschewsky 10
Jiang et al., Phys. Rev. Lett. 97, 217202 (2006).
0
1
2Gd
21(Fe
90Co
10)79
2.45 mT/(10
7 A/cm2)
HS
L (
mT
)
5.50 m
T/(10
7 A/cm
2 )
0.0 0.1 0.2 0.30.0
0.5
1.0 Gd28(Fe90Co10)72
0.59 mT/(107 A/cm
2)3.3
6 mT/(1
07 A/c
m2 )
HF
L (
mT
)
j (107 A/cm
2)
mz>0
-
Conclusion
Niklas Roschewsky 11
Acknowledgements:• P Gambardella and J. Mendil, ETH Zurich• Research was supported by the U.S. Department of Energy, the NSF E3S center • and the STARNET/FAME Center.
-
Niklas Roschewsky 12
-
Temperature dependence of the AHE
Niklas Roschewsky 13
0 100 200 300-3
-2
-1
0
1
2
3
RA
HE (
)
Temperature (K)
Gd21
(Fe90
Co10
)79
Gd28
(Fe90
Co10
)72
BOOP
= 50 mTj = 3104 A/cm
2
-
Temperature dependence of the AHE
Niklas Roschewsky 14
-100 -80 -60 -40 -20 0 20 40 60 80 100-4
-2
0
2
I = 100 A Gd21(Fe90Co10)79
T = 300 K
T = 200 K
T = 100 K
T = 50 K
T = 10 KRH (
)
Field (mT)
-200 -100 0 100 200-3.0
-1.5
0.0
1.5
3.0Gd
28(Fe
90Co
10)72
R (
)
B (mT)
300 K
100 K
60 K
40 K
10 K
I = 100 A
-
Temperature dependence of mTM
Niklas Roschewsky 15
