Two versions of magnetic field free spin torque oscillators with in- and out-of-plane spin polarizers are proposed. The field free spin torque oscillators comprise two spin valve stacks with a common free magnetic layer featuring an out-of-plane anisotropy. Their operation frequencies are controlled by the dimensions of the free layer and can also be tuned by the applied currents. Large and stable magnetization precessional motion of the whole shared free layer for both oscillators are obtained. The structure with in-plane polarizers allows more efficient microwave power extraction of the large in-plane magnetization precession of the free layer.

1.
2.
J.
Slonczewski
,
J. Magn. Magn. Mater.
159
,
L1
(
1996
).
3.
M.
Tsoi
,
A. G. M.
Jansen
,
J.
Bass
,
W.-C.
Chiang
,
M.
Seck
,
V.
Tsoi
, and
P.
Wyder
,
Phys. Rev. Lett.
80
,
4281
(
1998
).
4.
S. I.
Kiselev
,
J. C.
Sankey
,
I. N.
Krivorotov
,
N. C.
Emley
,
R. J.
Schoelkopf
,
R. A.
Buhrman
, and
D. C.
Ralph
,
Nature
425
,
380
(
2003
).
5.
C.
Boone
,
J. A.
Katine
,
J. R.
Childress
,
J.
Zhu
,
X.
Cheng
, and
I. N.
Krivorotov
,
Phys. Rev. B
79
,
140404
(
2009
).
6.
G.
Finocchio
,
N.
Maugeri
,
L.
Torres
, and
B.
Azzerboni
,
IEEE Trans. Magn.
46
,
1523
(
2010
).
7.
D. V.
Berkov
,
C. T.
Boone
, and
I. N.
Krivorotov
,
Phys. Rev. B
83
,
054420
(
2011
).
8.
Z.
Zeng
,
G.
Finocchio
,
B.
Zhang
,
P. K.
Amiri
,
J. A.
Katine
,
I. N.
Krivorotov
,
Y.
Huai
,
J.
Langer
,
B.
Azzerboni
,
K. L.
Wang
, and
H.
Jiang
,
Sci. Rep.
3
,
1426
(
2013
).
9.
T.
Gilbert
,
Phys. Rev.
100
,
1243
(
1955
).
10.
J. E.
Miltat
and
M. J.
Donahue
, “
Numerical micromagnetics: Finite difference methods
,” in
Handbook of Magnetism and Advanced Magnetic Materials
(
John Wiley & Sons, Ltd.
,
2007
).
11.
J.
Xiao
,
A.
Zangwill
, and
M. D.
Stiles
,
Phys. Rev. B
70
,
172405
(
2004
).
12.
D.
Nikonov
,
G.
Bourianoff
, and
T.
Ghani
,
IEEE Electron Device Lett.
32
,
1128
(
2011
).
13.
D.
Nikonov
,
G.
Bourianoff
, and
T.
Ghani
, in
Proceedings of the 11th IEEE Conference on Nanotechnology (IEEE-NANO)
(
2011
), pp.
1384
1388
.
14.
M.
Donahue
and
D.
Porter
, “
OOMMF user's guide, version 1.0
,”
Interagency Report No. NISTIR 6376, National Institute of Standards and Technology, Gaithersburg, MD
,
1999
.
15.
A. V.
Khvalkovskiy
,
K. A.
Zvezdin
,
Y. V.
Gorbunov
,
V.
Cros
,
J.
Grollier
,
A.
Fert
, and
A. K.
Zvezdin
,
Phys. Rev. Lett.
102
,
067206
(
2009
).
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