We investigated postannealing temperature dependence of the structural and magnetic properties of Co2Ti0.5Mn0.5Al and Co2Ti0.5Mn0.5Si films. It was observed that the Co2Ti0.5Mn0.5Al film formed an ordered L21 structure and an ordered B2 structure after postannealing at above 873 K and below 773 K, respectively. The Co2Ti0.5Mn0.5Si film deposited with substrate heating at above 473 K formed an ordered L21 structure. The obtained magnetoresistance ratio for a junction using an L21 ordered Co2Ti0.5Mn0.5Si electrode was 12.5% at room temperature (RT). The estimated spin polarization of the Co2Ti0.5Mn0.5Si film was 0.14 at RT. The magnetoresistance ratios of a junction using a B2 ordered Co2Ti0.5Mn0.5Al electrode were 65.8% at RT and 128.4% at 7 K. The estimated spin polarizations of the Co2Ti0.5Mn0.5Al film were 0.56 at RT and 0.78 at 7 K.

1.
T.
Miyazaki
and
N.
Tezuka
,
J. Magn. Magn. Mater.
139
,
L231
(
1995
).
2.
J. S.
Moodera
,
L. R.
Kinder
,
T. M.
Wong
, and
R.
Meservey
,
Phys. Rev. Lett.
74
,
3273
(
1995
).
3.
S.
Yuasa
,
T.
Nagahama
,
A.
Fukushima
,
Y.
Suzuki
, and
K.
Ando
,
Nature Mater.
3
,
868
(
2004
).
4.
S. S. P.
Parkin
,
C.
Kaiser
,
A.
Panchula
,
R. M.
Rice
,
B.
Hughes
,
M.
Samant
, and
S.-H.
Yang
,
Nature Mater.
3
,
862
(
2004
).
5.
S.
Ikeda
,
J.
Hayakawa
,
Y.
Ashizawa
,
Y. M.
Lee
,
K.
Miura
,
H.
Hasegawa
,
M.
Tsunoda
,
F.
Matsukura
, and
H.
Ohno
,
Appl. Phys. Lett.
93
,
082508
(
2008
).
6.
W. H.
Butler
,
X.-G.
Zhang
,
T. C.
Schulthess
, and
J. M.
Maclaren
,
Phys. Rev. B
63
,
054416
(
2001
).
7.
N.
Tezuka
,
N.
Ikeda
,
S.
Sugumoto
, and
K.
Inomata
,
Appl. Phys. Lett.
89
,
252508
(
2006
).
8.
J.
Kübler
,
A. R.
Williams
, and
C. B.
Sommers
,
Phys. Rev. B
28
,
1745
(
1983
).
9.
S.
Ishida
,
D.
Fujii
,
S.
Kashiwagi
, and
S.
Asano
,
J. Phys. Soc. Jpn.
64
,
2152
(
1995
).
10.
G. H.
Fecher
,
H. C.
Kandpal
,
S.
Wurmehl
,
C.
Felser
, and
G.
Schönhense
,
J. Appl. Phys.
99
,
08J106
(
2006
)
11.
J.
Kübler
,
G. H.
Fecher
, and
C.
Felser
,
Phys. Rev. B
76
,
024414
(
2007
).
12.
Y.
Miura
,
K.
Nagao
, and
M.
Shirai
,
Phys. Rev. B
69
,
144413
(
2004
).
13.
Y.
Miura
,
M.
Shirai
, and
K.
Nagao
,
J. Appl. Phys.
99
,
08J112
(
2006
)
14.
Y.
Sakuraba
,
J.
Nakata
,
M.
Oogane
,
H.
Kubota
,
Y.
Ando
,
A.
Sakuma
, and
T.
Miyazaki
,
Jpn. J. Appl. Phys., Part 2
44
,
L1100
(
2005
).
15.
N.
Tezuka
,
N.
Ikeda
,
F.
Mitsuhashi
, and
S.
Sugimoto
,
Appl. Phys. Lett.
94
,
162504
(
2009
).
16.
N.
Tezuka
,
N.
Ikeda
,
A.
Miyazaki
,
S.
Sugimoto
,
M.
Kikuchi
, and
K.
Inomata
,
Appl. Phys. Lett.
89
,
112514
(
2006
).
17.
H.
Kubota
,
J.
Nakata
,
M.
Oogane
,
Y.
Ando
,
A.
Sakuma
, and
T.
Miyazaki
,
Jpn. J. Appl. Phys., Part 2
43
,
L984
(
2004
).
You do not currently have access to this content.