We investigate the magneto-optical properties of a nonstoichiometric, epitaxial Co2Mn0.77Ge0.42(001) film grown on a MgO-buffered MgO(001) single-crystal substrate. Magneto-optical Kerr effect magnetometry indicates that the sample has strong uniaxial anisotropy, whereas the easy and hard axes of magnetization are tilted by 10° with respect to the [110] and [11¯0] directions, respectively. A modest quadratic Kerr effect with an amplitude of 0.4 mdeg was observed. Brillouin light scattering spectroscopy was used to find that the exchange constant A, spin-wave stiffness D, and saturation magnetization Ms are 22.5 pJ/m, 413meVÅ2, and 6.43μB/f.u., respectively. The saturation magnetization value suggests that the Slater–Pauling rule might apply to such nonstoichiometric compositions.

1.
S.
Fujii
,
S.
Sugimura
,
S.
Ishida
, and
S.
Asano
,
J. Phys. Condens. Matter
2
,
8583
(
1990
).
2.
S.
Ishida
,
S.
Fujii
,
S.
Kashiwagi
, and
S.
Asano
,
J. Phys. Soc. Jpn.
64
,
2152
(
1995
).
3.
S.
Picozzi
,
A.
Continenza
, and
A.
Freeman
,
Phys. Rev. B
66
,
094421
(
2002
).
4.
I.
Galanakis
,
P.
Mavropoulos
, and
P. H.
Dederichs
,
J. Phys. D: Appl. Phys.
39
,
765
(
2006
).
5.
P. J.
Webster
,
J. Phys. Chem. Solids
32
,
1221
(
1971
).
6.
T.
Marukame
,
T.
Kasahara
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
Jpn. J. Appl. Phys., Part 2
44
,
L521
(
2005
).
7.
M.
Yamamoto
,
T.
Marukame
,
T.
Ishikawa
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Arita
,
J. Phys. D: Appl. Phys.
39
,
824
(
2006
).
8.
T.
Ishikawa
,
T.
Marukame
,
H.
Kijima
,
K. -i.
Matsuda
,
T.
Uemura
,
M.
Arita
, and
M.
Yamamoto
,
Appl. Phys. Lett.
89
,
192505
(
2006
).
9.
T.
Ishikawa
,
S.
Hakamata
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
J. Appl. Phys.
103
,
07A919
(
2008
).
10.
T.
Ishikawa
,
N.
Itabashi
,
T.
Taira
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
J. Appl. Phys.
105
,
07B110
(
2009
).
11.
T.
Taira
,
T.
Ishikawa
,
N.
Itabashi
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
Appl. Phys. Lett.
94
,
072510
(
2009
).
12.
T.
Taira
,
T.
Ishikawa
,
N.
Itabashi
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
J. Phys. D: Appl. Phys.
42
,
084015
(
2009
).
13.
T.
Ishikawa
,
H. –x.
Liu
,
T.
Taira
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
Appl. Phys. Lett.
95
,
232512
(
2009
).
14.
R.
Shan
,
H.
Sukegawa
,
W. H.
Wang
,
M.
Kodzuka
,
T.
Furubayashi
,
T.
Ohkubo
,
S.
Mitani
,
K.
Inomata
, and
K.
Hono
,
Phys. Rev. Lett.
102
,
246601
(
2009
).
15.
T.
Marukame
and
M.
Yamamoto
,
J. Appl. Phys.
101
,
083906
(
2007
).
16.
T.
Ishikawa
,
N.
Itabashi
,
T.
Taira
,
K. -i.
Matsuda
,
T.
Uemura
, and
M.
Yamamoto
,
Appl. Phys. Lett.
94
,
092503
(
2009
).
17.
V.
Drewello
,
J.
Schmalhorst
,
A.
Thomas
, and
G.
Reiss
,
Phys. Rev. B
77
,
014440
(
2008
).
18.
P.
Mavropoulos
,
M.
Ležaić
, and
S.
Blügel
,
Phys. Rev. B
72
,
174428
(
2005
).
19.
O.
Gaier
,
J.
Hamrle
,
S. J.
Hermsdoerfer
,
H.
Schultheiß
,
B.
Hillebrands
,
Y.
Sakuraba
,
M.
Oogane
, and
Y.
Ando
,
J. Appl. Phys.
103
,
103910
(
2008
).
20.
J.
Hamrle
,
S.
Blomeier
,
O.
Gaier
,
B.
Hillebrands
,
K.
Postava
,
H.
Schneider
,
G.
Jakob
, and
C.
Felser
,
J. Phys. D: Appl. Phys.
40
,
1563
(
2007
).
21.
J.
Hamrle
,
S.
Blomeier
,
O.
Gaier
,
B.
Reuscher
,
A.
Brodyanski
,
M.
Kopnarski
,
K.
Postava
,
H.
Schneider
,
G.
Jakob
,
C.
Felser
, and
B.
Hillebrands
,
J. Phys. D: Appl. Phys.
40
,
1558
(
2007
).
22.
J.
Hamrle
,
S.
Blomeier
,
O.
Gaier
,
B.
Hillebrands
,
R.
Schäfer
, and
M.
Jourdan
,
J. Appl. Phys.
100
,
103904
(
2006
).
23.
S.
Trudel
,
G.
Wolf
,
H.
Schultheiss
,
J.
Hamrle
,
B.
Hillebrands
,
T.
Kubota
, and
Y.
Ando
,
Rev. Sci. Instrum.
81
,
026105
(
2010
).
24.
O.
Gaier
,
J.
Hamrle
,
S.
Trudel
,
B.
Hillebrands
,
H.
Schneider
, and
G.
Jakob
,
J. Phys. D: Appl. Phys.
42
,
232001
(
2009
).
25.
J.
Hamrle
,
O.
Gaier
,
S. -G.
Min
,
B.
Hillebrands
,
Y.
Sakuraba
, and
Y.
Ando
,
J. Phys. D: Appl. Phys.
42
,
084005
(
2009
).
26.
O.
Gaier
,
J.
Hamrle
,
S.
Trudel
,
A.
Conca Parra
,
B.
Hillebrands
,
E.
Arbelo
,
C.
Herbort
, and
M.
Jourdan
,
J. Phys. D: Appl. Phys.
42
,
084004
(
2009
).
27.
M.
Belmeguenai
,
F.
Zighem
,
G.
Woltersdorf
,
Y.
Roussigné
,
S. M.
Chérif
,
K.
Westerholt
, and
G.
Bayreuther
,
J. Magn. Magn. Mater.
321
,
750
(
2009
).
28.
M.
Belmeguenai
,
F.
Zighem
,
Y.
Roussigné
,
S. -M.
Chérif
,
P.
Moch
,
K.
Westerholt
,
G.
Woltersdorf
, and
G.
Bayreuther
,
Phys. Rev. B
79
,
024419
(
2009
).
29.
The L21 structure for a M2MZ full-Heusler compound is described by the Fm3¯m/225 space group. The M atoms occupy the Wyckoff 8c positions (14,14,14), while the M and Z atoms are located at the 4a (0,0,0) and 4b(12,12,12) positions, respectively.
30.
K.
Postava
,
H.
Jaffres
,
A.
Schuhl
,
F. N. V.
Dau
,
M.
Goiran
, and
A. R.
Fert
,
J. Magn. Magn. Mater.
172
,
199
(
1997
).
31.
K.
Postava
,
D.
Hrabovský
,
J.
Pištora
,
A. R.
Fert
,
Š.
Višňovský
, and
T.
Yamaguchi
,
J. Appl. Phys.
91
,
7293
(
2002
).
32.
B.
Hillebrands
,
Rev. Sci. Instrum.
70
,
1589
(
1999
).
33.
T.
Ambrose
,
J. J.
Krebs
, and
G. A.
Prinz
,
Appl. Phys. Lett.
76
,
3280
(
2000
).
34.
F. Y.
Yang
,
C. H.
Shang
,
C. L.
Chien
,
T.
Ambrose
,
J. J.
Krebs
,
G. A.
Prinz
,
V. I.
Nikitenko
,
V. S.
Gornakov
,
A. J.
Shapiro
, and
R. D.
Shull
,
Phys. Rev. B
65
,
174410
(
2002
).
35.
R. M.
Osgood
 III
,
S. D.
Bader
,
B. M.
Clemens
,
R. L.
White
, and
H.
Matsuyama
,
J. Magn. Magn. Mater.
182
,
297
(
1998
).
36.
P. K.
Muduli
,
W. C.
Rice
,
L.
He
, and
F.
Tsui
,
J. Magn. Magn. Mater.
320
,
L141
(
2008
).
37.
P. K.
Muduli
,
W. C.
Rice
,
L.
He
,
B. A.
Collins
,
Y. S.
Chu
, and
F.
Tsui
,
J. Phys.: Condens. Matter
21
,
296005
(
2009
).
38.
S. S.
Yan
,
R.
Schreiber
,
P.
Grünberg
, and
R.
Schäfer
,
J. Magn. Magn. Mater.
210
,
309
(
2000
).
39.
M.
Buchmeier
,
R.
Schreiber
,
D. E.
Bürgler
, and
C. M.
Schneider
,
Phys. Rev. B
79
,
064402
(
2009
).
40.
At normal incidence, A=(ño2φ)/[ñ2(ño2ñ2)] and B=ño/[ñ(ño2ñ2)], where φ is the angle of incidence and ñ and ño are the complex refractive indices of the material and the incident medium, respectively. This neglects the AlOx capping layer, the MgO barrier, and the finite thickness of the magneto-optically active film.
41.
B.
Hillebrands
, in
Light Scattering in Solids VII
, edited by
M.
Cardona
and
G.
Güntherodt
(
Springer-Verlag
,
Heidelberg
,
2000
).
42.
Note that we determine the volume magnetization saturation, which we then convert to a magnetization per unit cell.
43.
B.
Hillebrands
, in
Modern Techniques for Characterizing Magnetic Materials
, edited by
Y.
Zhu
(
Kluwer Academic
,
Boston
,
2005
).
44.
B.
Hillebrands
,
Phys. Rev. B
41
,
530
(
1990
).
45.
J.
Hamrle
,
S.
Trudel
,
O.
Gaier
, and
B.
Hillebrands
(unpublished).
46.
S.
Picozzi
,
A.
Continenza
, and
A. J.
Freeman
,
J. Appl. Phys.
94
,
4723
(
2003
).
47.
S.
Picozzi
,
A.
Continenza
, and
A. J.
Freeman
,
Phys. Rev. B
69
,
094423
(
2004
).
48.
S.
Picozzi
and
A. J.
Freeman
,
J. Phys.: Condens. Matter
19
,
315215
(
2007
).
49.
K.
Özdoğan
,
I.
Galanakis
,
E.
Şaşioğlu
, and
B.
Aktaş
,
Solid State Commun.
142
,
492
(
2007
).
50.
I.
Galanakis
,
K.
Özdoğan
,
B.
Aktaş
, and
E.
Şaşioğlu
,
Appl. Phys. Lett.
89
,
042502
(
2006
).
51.
I.
Galanakis
,
P. H.
Dederichs
, and
N.
Papanikolaou
,
Phys. Rev. B
66
,
174429
(
2002
).
52.
B.
Hülsen
,
M.
Scheffler
, and
P.
Kratzer
,
Phys. Rev. B
79
,
094407
(
2009
).
You do not currently have access to this content.