metamagnetic shape memory effect in nimnbased heusler-type alloys
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Metamagnetic shape memory effect in NiMn-based Heusler-type alloys
ARTICLE in JOURNAL OF MATERIALS CHEMISTRY JANUARY 2008
Impact Factor: 7.44 DOI: 10.1039/b713947k
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Tohoku University
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Wataru Ito
Sendai National College of Technology
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Metamagnetic shape memory effect in NiMn-based Heusler-type alloys
Ryosuke Kainuma,*a Katsunari Oikawa,b Wataru Ito,b Yuji Sutou,b Takeshi Kanomatac and Kiyohito Ishidab
Received 11th September 2007, Accepted 7th January 2008
First published as an Advance Article on the web 21st January 2008
DOI: 10.1039/b713947k
Recent findings on Heusler-type alloys in NiMnIn- and NiMnSn-based systems show a specific
martensitic (i.e., diffusionless) transformation from a ferromagnetic parent (P) phase to an
antiferromagnetic-like martensite (M) phase. In this paper, the magnetic and martensitic properties
and the details of the magnetic field-induced shape memory effect (SME) are introduced in
NiMnIn-based alloys. The martensitic transformation temperatures of these alloys significantly
decrease with the application of a magnetic field, and a metamagnetic phase transformation occurs
from the M phase to the P phase. By using this transition, a magnetic field-induced strain of
approximately 3%, namely, a metamagnetic SME, is confirmed.
Introduction
Based on diffusionless phase transformation, which is termed
martensitic transformation, the shape memory effect (SME) in
alloys is known to be unique behavior by which an alloy
deformed in the low-temperature phase recovers its original
shape by reverse transformation upon heating to the reverse
transformation temperature. This effect was first observed in
AuCd alloys in 1951 and became well known with its discovery
in TiNi alloys in 1963.1 TiNi alloys are the most familiar shape
memory alloys (SMA) with applications in various fields such as
medical guidewires, cellar-phone antennae, and smart actuators.
Because the strain and stress generated by the SME are
extremely large as compared to those generated in piezoelectric
and magnetostrictive materials, SMAs are potential candidates
for actuators such as motors and supersonic oscillators.
However, since the output actuation in SMAs occurs through
temperature change for an input signal, it is not easy to obtain
a rapid response to the input signal at frequencies greater than
5 Hz because the thermal conductivity of the alloys is a ratedetermining factor of the response.2 This fatal drawback restricts
the application of SMAs as actuators. Magnetic shape memory
alloys (MSMAs) in which a rapid output strain is achieved
through the application of a magnetic field have been developed
to overcome this obstacle.
Since Ullakko et al.3 first reported the existence of magnetic
field-induced strain (MFIS) in ferromagnetic Ni2MnGa single
crystals in 1996, research in this field has drastically progressed
and current studies have reported large MFIS values greater
than 9%.4 The MFIS obtained in the ferromagnetic Ni2MnGa
single crystal is explained by the rearrangement of martensite
variants due to an external field. When the crystalline magnetic
anisotropy energy is greater than the energy driving the variantboundaries, the angle between the magnetization and the applied
magnetic field directions is lowered by not only the independent
rotation of magnetization but also the variant rearrangement in
order that the magnetic easy axis is aligned parallel to the
magnetic field direction. Thus, the variant rearrangement yields
the MFIS, which is comparable to the strain induced by the
monoaxial stress applied to the martensite (M) phase. Details
on the MFIS in Ni2MnGa alloys have recently been reviewed
Ryosuke Kainuma
Ryosuke Kainuma was born in
Hokkaido, Japan in 1961. He
received diploma and Dr Eng
degrees in materials science
from Tohoku University in
1983 and 1988, respectively.
He is a full professor at
IMRAM, Tohoku University.
His research field is materials
science, covering phase
diagrams, phase transforma-
tions and microstructure control
of alloys and intermetallic
compounds. Katsunari Oikawa
Katsunari Oikawa was born in
Aomori, Japan in 1968. He
studied materials science at
Tohoku University and received
his PhD at the same University
in 1996. He is an associate
professor of the solidification
process at Department of
Metallurgy, Graduate School
of Engineering, Tohoku
University. His current research
field is phase diagrams, thermo-
dynamic and microstructure
control.
aInstitute of Multidisciplinary Research for Advanced Materials(IMRAM), Tohoku University, Sendai, 980-8577, Japan. E-mail:[email protected] of Materials Science, Graduate School of Engineering,Tohoku University, Sendai, 980-8579, JapancFaculty of Engineering, Tohoku Gakuin University, Tagajo, 980-8579,Japan
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by Marioni et al.5 Although large output strain and rapid
response can be confirmed in Ni2MnGa alloys, the output stress
is principally lower than 5 MPa.6 Furthermore, the significant
brittleness of Ni2MnGa single crystals is a serious problem
that prevents the application of this material. On the other
hand, it has been reported that some trials use phase transforma-
tion to obtain an MFIS.79 However, in Ni2MnGa alloys, a huge
magnetic field is required to obtain magnetic field-induced trans-
formation because both the parent (P) and M phases exhibitferromagnetism and the saturated magnetization of the M phase
is comparable to that of the P phase.10
Since 2000, the present authors have developed many Ni-based
MSMAs such as NiMnAl,11,12 NiCoAl,13,14 NiCoGa,14,15 and
NiFeGa,16,17 and clarified the characteristic features of their
magnetic and martensitic transformations. Very recently, we
observed an unusual transformation from the ferromagnetic P
phase to the antiferromagnetic-like M phase in NiMnIn- and
NiMnSn-based Heusler alloys,18 which exhibit behaviors
completely different from those of the previous MSMAs. In this
paper, the magnetic and mechanical properties, mainly those of
the NiMnIn-based alloys, are reviewed and the SME induced
by a magnetic field is introduced.
Metamagnetic phase transition in NiMnIn-based
alloys
Although stoichiometric Ni2MnIn and Ni2MnSn Heusler alloys
with bcc-based (L21) crystal structures, as shown inFig. 1(a), are
known to exhibit ferromagnetism,19,20 martensitic transforma-
tion in these alloys has not yet been reported. The authors
observed that martensitic transformation from the Heusler-type
P phase to the monoclinic or orthorhombic M phase occurs in
the NiMnNi2MnX sections.18 Fig. 1(b)shows the thermomag-
netization curve of the Ni50Mn34In16alloy (at%) for a magnetic
field of 0.05 T.21 The Curie temperature Tc of the P phase is
detected at around 280 K, and the martensitic transformation
starting temperatureTMsappears at around 230 K. It is observedthat the magnetization drastically decreases with temperature
from the TMs to the martensitic transformation finishing
temperatureTMfand that the thermal hysteresis is approximately
20 K. Such thermomagnetization behavior in a weak magnetic
field is sometimes observed in the M phase of conventional
FSMAs with large crystalline magnetic anisotropy energy.10
However, in the present case, the magnetization of the M phase
is very small, even in the presence of strong magnetic fields.
Fig. 222 shows the thermomagnetization curves for magnetic
fields of 0.05 T and 7 T and the magnetization curves at various
temperatures for a Ni46Mn41In13 alloy whose composition is
slightly different from that of the previous alloy. InFig. 2(a), it
is observed that the difference in the saturated magnetizationbetween the P and M phases is approximately 100 emu g1 and
that the TMs and TMf temperatures and the temperatures TAsand TAf at which the reverse transformation starts and ends,
respectively, decrease by 4050 K due to the increase in the
magnetic field from 0.05 T to 7 T. This result suggests that at
temperatures between 180 and 220 K, the M phase transforms
to the P phase due to application of the magnetic field of
7 T. This behavior, i.e., the magnetic field-induced reverse
Fig. 1 Crystal structure of Ni2MnZ Heusler phase (a) and thermomag-
netization curve21 of Ni50Mn34In16 in a magnetic field ofH 0.05 (b).
Magnetic moments of Mn atoms in each state are schematically indicated
with arrows in insets of (b), where M(AF?), P(FM) and P(PM) are the
martensite phase with antiferromagnetic-like magnetism and the parent
phases with ferromagnetism and paramagnetism, respectively.
Fig. 2 Thermomagnetization curves in magnetic fields of H 0.05
and 7 T (a) and magnetization curves at various temperatures (b) in
the Ni46Mn41In13alloy.22
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transformation (MFIRT), was confirmed in the magnetization
curves at 180 and 200 K, as shown in Fig. 2(b). InFig. 2(b), it
is observed that the curves at 273 K and 100 K that correspond
to the P and M phases exhibit simple ferromagnetic and weak-
magnetic behavior, respectively; however, those at 180 and 200
K show drastic variations in magnetization due to the MFIRT
at approximately 5 and 7.5 T, respectively, at which the weak
magnetism of the M phase appears to be antiferromagnetic
because the L10 martensite phase in the binary NiMn alloyexhibits antiferromagnetism.23 Such a magnetic field-induced
transformation, the so-called metamagnetic phase transition,
has also been reported in alloys such as MnAs and FeSiLa24
and has recently attracted considerable interest due to the
possibility for the application of magnetocaloric materials in
magneticrefrigeration systems. In the NiMnIn alloy, the magnetic
entropy change induced by a magnetic field is evaluated from the
magnetization curves inFig. 2(b)to be approximately 13 J kg1
K1 at 190 K,22 and this alloy is a promising magnetocaloric
material. Thus, the decrease in the martensitic transformation
temperatures can be attributed to the magnetically induced
stabilization of the P phase, which is mainly caused by the differ-
ence in the saturated magnetization between the P and M phases.Because theTcof the NiMnIn ternary alloys lies in the temper-
ature range between 280 and 300 K, it is difficult to obtain
a metamagnetic phase transition at room temperature. In order
to increase the Tc of the ternary alloys, we attempted the
substitution of Co for Ni. Fig. 3 shows the phase diagram for
the martensitic and magnetic transformations determined by
differential scanning calorimetric (DSC) measurements in the
Ni(50x)CoxMn(50y)Iny (x: 0, 5, and 7.5; y: 1016) alloys,21
where the solid and broken lines indicate TMs and Tc, respec-
tively. It is observed that the value ofTc increases with the Co
composition and is almost independent of the In composition,
whereas the value ofTMsdecreases with increase in the Co and
In compositions. Furthermore, abnormal behavior of TMs isdetected, as shown in Fig. 3, i.e., although the variation in the
temperature is almost linear to the In composition in the para-
magnetic region of the P phase, the value ofTMsdeviates from
the linear relation and decreases in the ferromagnetic region.
Figs. 4(a) and (b)show the thermomagnetization curves in the
magnetic fields of 0.05 and 7 T and the magnetization curves at
200, 270, 290, and 320 K in the Ni45Co5Mn36.7In13.3alloy, respec-
tively.25 The characteristic features of the quaternary alloy are
basically similar to those of the NiMnIn ternary alloy;
however, the decrease in the value ofTMs, which is only approx-
imately 25 K in a magnetic field of 7 T, is smaller than that in the
Ni46Mn41In13alloy. This issue is discussed in the next section. It
is also observed that the addition of Co results in a decrease in thesaturation magnetization in the M phase region. The origin of
this phenomenon is not yet clear, but it appears that the doped
Co has a strong magnetic interaction with Mn, which should
be dominant in the magnetic properties in this alloy. It should
be emphasized here that an apparent metamagnetic phase transi-
tion is detected at 290 K,as shown in Fig. 4(b). This indicates that
this quaternary alloy possibly has a magnetic field-induced SME
due to this metamagnetic phase transition at room temperature.
Transformation entropy change21
As shown inFigs. 2and4, while the TMsand TMftemperatures
decrease with increase in the magnetic field in all the alloys, thedegree of the decrease differs in the various alloys. For instance,
the decrease in the value ofTMs for a magnetic field of 7 T is
approximately 50 K in Ni46Mn41In13 but approximately 25 K
in Ni45Co5Mn36.7In13.3. The transformation temperature change
(DT) induced by the magnetic field change (DH) is approximately
given by the ClausiusClapeyron relation in the magnetic phase
diagram:
dH
dT
DS
DI
DTz
DI
DS
DH
(1)
Fig. 3 Composition dependence of indium on TMs and Tc for
Ni50MnIn, Ni45Co5MnIn and Ni42.5Co7.5MnIn alloys.21
Fig. 4 Thermomagnetization curves in magnetic fields of H 0.05
and 7 T (a) and magnetization curves at various temperatures (b) in
the Ni45Co5Mn36.7In13.3alloy.25
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where T denotes the absolute temperature; H, the applied
magnetic field; and DIand DS, the differences in magnetization
and entropy between the P and M phases, respectively.25 Accord-
ing to eqn (1), the decrease in the value ofTMsinduced by the
magnetic field is proportional to the value of DHwhen DI/DS
is constant. In the NiMnIn and NiCoMnIn alloys shown in
Fig. 2 and 4, while the values of DI are approximately 100
emu/g in both the cases, the value ofDT for the same magnetic
field DHis different in each case. This suggests that the differencein the values ofDT is due to the difference in the value ofDS
between these alloys. In fact, the values of DSexperimentally
determined by DSC measurements in the Ni46Mn41In13 and
Ni45Co5Mn36.7In13.3alloys are 17.1 J K1 kg1 21 and 27.0 J K1
kg1,25 and the change in the value ofTMs, namely, DT, estimated
by Eq. 1 on the basis of the experimental values ofDIand DHare
41 and 26 K, respectively, which are in agreement with the
experimental values. This result implies that a large value of
DI and a small value of DSmust accompany the martensitic
transformation if a large variation in TMsis desired.
Fig. 5(a)shows the value ofDSdetermined by DSC measure-
ments for Ni(50x)CoxMn(50y)Inyalloys.21 In ordinary paramag-
netic SMAs such as TiNi and Cu-based alloys, the value ofDSinthe martensitic transformation, which is mainly caused by the
difference in the vibration entropy between the P and M
phases,26 is not drastically altered with variation in the alloy
composition when the crystal structures of both the P and M
phases are fixed.27 In the transformation from the paramagnetic
P to the antiferromagnetic-like M phase, which is indicated by
the open symbols inFig. 5(a), the values ofDSslightly decrease
with increase in the In composition at approximately 50 J K1
kg1 in the ternary system and at 6070 J K1 kg1 in the quater-
nary system, which indicates normal behavior. On the other
hand, the values ofDS drastically decrease with increase in the
In composition during the transformation from the ferromag-
netic P to the antiferromagnetic-like M phase, as indicated by
the closed symbols in Fig. 5(a), thereby exhibiting a singularpoint at compositions in which the P phase changes from the
paramagnetic to the ferromagnetic condition. Since the crystal
structure of the M phase obtained from the paramagnetic P
phase is not basically different from that obtained from the
ferromagnetic P phase,21 this behavior cannot be attributed to
the change in the crystal structure. Such experimental results
on theTMstemperature and the value ofDScan be qualitatively
explained by a thermodynamic consideration that takes into
account the magnetic contribution to the Gibbs energy of the
P phase.21 Fig. 5(b) shows the relationship between the values
ofDSagainst the temperatures Tc TMs. A strong correlation
expected between the temperatures Tc TMs and DS was
confirmed, while the curve for the 0Co alloys does not coincidewith that for the quaternary alloys. This relationship implies
that a small value ofDScan be obtained from a specimen with
a large value ofTc TMs.
Metamagnetic shape memory effect25
Figs. 6(a) and (b) show the stressstrain curves of the
Ni45Co5Mn36.7In13.3 and Ni45Co5Mn36.5In13.5 alloys, respec-
tively, to which were applied a compressive strain of approxi-
mately 7% at 298 K.25 The stressstrain characteristics at the
testing temperature of Tt 298 K are dependent on the TAsand TAf temperatures of the specimens, that is, when TAf< Tt,
typical pseudoelastic (PE) behavior with a closed loop appeared,as shown inFig. 6(b), and when TAf> Tt, the deformed strain
remained even after the stress was removed, as shown in
Fig. 6(a). An almost perfect SM effect in the as-deformed
specimens was confirmed by dilatometric examination whilst
heating to 373 K. These results confirm that the NiCoMnIn
alloys are generally SM and PE materials.
The shape recovery induced by the magnetic field was
examined by a three-terminal capacitance method with the
Ni45Co5Mn36.7In13.3specimen.25 Fig. 7shows the recovery strain
induced by the magnetic field at 298 K at which a compressive
pre-strain of approximately 3% was applied along the direction
plotted with a filled circle in the stereographic triangle shown
in Fig. 7, and the magnetic field was applied vertically to thecompressive axis of the specimen. The recovery strain started
to increase at approximately 2 T and rose sharply at approxi-
mately 3.6 T and then gradually increased to 8 T with the
magnetic field. A recovery strain of approximately 2.9%, almost
equal to the pre-strain of 3%, was obtained with a magnetic field
of 8 T. However, only a slight change in length was observed
from approximately 3 T when the magnetic field was removed.
This behavior induced by the magnetic field is comparable to
the general SM effect due to the reverse transformation induced
by heating, as shown in Fig. 6(a), where the application of
magnetic field corresponds to heating. We propose that the
Fig. 5 Entropy change DSdue to martensitic transformation vs. (a)
indium composition and (b) Tc TMs. While the transformation from
the paramagnetic parent phase shows a large DSas plotted with open
symbols in (a), the DSdrastically decreases in the transformation from
ferromagnetic parent phase as indicated with solid symbols.21
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SM effect due to MFIRT, which is a metamagnetic transition, be
called the metamagnetic shape memory effect (MMSME) and
that such a SMA be termed a metamagnetic shape memory
alloy (MMSMA).25
In contrast with the previous ferromagnetic SMAs such as
Ni2MnGa and FePd, this MMSMA system has many advan-
tages for practical applications. The most important advantage
may be that the present MFIS can yield a high output stress
due to the magnetic field. The ClausiusClapeyron relation on
the critical stress for the stress-induced martensitic transforma-
tion is given by
dsc
dT
DS
3,Vm (2)
where 3denotes the difference in the lattice strain between the P
and M phases in a corresponding direction and Vmdenotes the
molar volume of the alloy. The magnetic field-induced change
in the critical stress corresponds to the output stress obtained
by the combination with eqn (1), as follows:
DsczDS
3,Vm,DTz
DI
3,Vm,DH (3)
This equation shows that the output stress yielded by the
MMSMA is proportional to the magnetic field. In eqn (3),
the fact that Dscis inversely proportional to 3may be one of themost important points. The parameter 3 significantly depends on
the deformation mode and the direction of monoaxial strain
applied in a single crystal. For instance, in the tensile mode for
a NiFeGa single crystal,28 which has a crystal structure in the
M phase similar to that of the NiCoMnIn alloy, the value of 3
is approximately 6% along the p direction but only
approximately 0.6% along the p direction. This suggests
that the value ofDsccan be varied by the selection of the defor-
mation direction in a single crystal. By using some appropriate
data for the NiCoMnIn alloy and the values of3 for the NiFeGa
single crystal, the value ofDsc in the tensile deformation mode
induced by a magnetic field of 1 T is evaluated to be
approximately 13 and 130 MPa along the p and pdirections, respectively. Since the value of 3continuously varies
with change in the direction from pto p, the output
stress can be selected by the selection of the deformation direction
in a single crystal. However, it is impossible to obtain a combina-
tion of large values ofDscand 3over the magnetic input energy
corresponding to DI DH. It is worth noting that eqn (3) only
expresses the conversion between the magnetic and mechanical
energies. Thus, in NiCoMnIn alloys, the output stress is expected
to be greater than that in NiMnGa alloys, whereas the output
strain is relatively smaller. Very recently, MFIRT under a static
compressive stress of 50 MPa was experimentally confirmed in
NiCoMnIn alloys by using X-ray diffraction examination by
Wang et al.29 It is known that monoaxial strain generallystabilizes the M phase, as given by eqn (2). However, the
magnetic field always stabilizes the P phase in the MMSMA.
This relationship suggests that precise control of the strain is
possible by a combination of the strain and magnetic field.
Recently, the MMSME was also confirmed in polycrystalline
NiCoMnSn alloys.30 The MMSME appears not only in single
crystals but also in polycrystals and reversible strains as the
two-way memory effect is obtained by deformation of the
polycrystalline specimen.30 The NiCoMnSn alloy system, which
does not include expensive elements, may be the most promising
MMSMA candidate for industrial applications in the future.
Fig. 7 Recovery strain at 298 K induced by a magnetic field for the
Ni45Co5Mn36.7In13.3 single crystal in which a compressive pre-strain of
about 3% was applied, where the magnetic field was applied vertically
to the compressive axis of the specimen and the length change parallel
to the compressive axis was measured. Shape recovery is due to magnetic
field-induced reverse transformation which is termed the metamagnetic
shape memory effect.25
Fig. 6 Compressive stressstrain curves for (a) Ni45Co5Mn36.7In13.3and (b) Ni45Co5Mn36.5In13.5 single crystals at Tt 298 K. The
Ni45Co5Mn36.5In13.5 alloy in (b) shows almost perfect pseudoelasticity.
Almost perfect shape recovery due to heating to 373 K after deformation
was also confirmed by examination using a dilatometer for the
Ni45Co5Mn36.7In13.3alloy as demonstrated in (a).25 Here, shape memory
effect results from twin boundary deformation of the M phase and
reverse transformation induced by heating as demonstrated in (a). On
the other hand, pseudoelasticity is due to stress-induced martensitic
transformation during application of stress and reverse transformation
during release of stress as shown in (b).
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7/25/2019 Metamagnetic shape memory effect in NiMnbased Heusler-type alloys
7/7
In the MMSME that does not require any change in
temperature, a rapid response to an input signal is expected.
Very recently, Sakonet al.31 reported that a Ni45Co5Mn36.7In13.3single crystal exhibited an almost perfect MMSME for a single
magnetic field pulse of 200 Hz, whose characteristic features
are similar to that in a static magnetic field.
Conclusion
The phase transformation from the ferromagnetic to the anti-
ferromagnetic phase has already been reported for several alloy
compounds and ceramics. In the NiMn-based alloys discussed
in this study, the magnetic transition occurs with the thermoelas-
tic martensite transformation accompanying the shape memory
effect and pseudoelasticity, which is different from that in the
previous materials. This combination of magnetic and structural
transitions has high potential for the development of many types
of multiferroic devices such as sensors, actuators, and thermo-
magnetic engines and can by controlled by three factors, namely,
temperature, stress, and magnetic field.
Since the reports on MMSMAs, many investigations have been
performed and some unique physical properties such as giantmagnetoresistance,32,33 giant magnetothermal conductivity,34
and inverse magnetocaloric effect35,36,37 have been reported. These
properties are also very interesting.
Acknowledgements
The authors are grateful to Mr Y. Imano, Dr H. Morito and
Prof. S. Okamoto, O. Kitakami and A. Fujita, Tohoku
University, for their assistance with the experiments. This study
was supported by a Grant-in-Aid from CREST, Japan Science
and Technology Agency (JST), Grants-in-Aid for Scientific
Research from the Japan Society for the Promotion of Science
(JSPS), Japan, and Global COE Project.
References
1 Shape Memory Materials, ed. K. Otsuka and C. M. Wayman,Cambridge University Press, UK, 1998.
2 M. V. Gandhi and B. S. Thompson, Smart Materials and Structures,Chapman & Hall, New York, 1992.
3 K. Ullakko, J. K. Huang, C. Kanter, V. V. Kokorin andR. C. OHandley, Appl. Phys. Lett., 1996, 69, 19661968.
4 A. Sozinov, A. A. Likhachev and K. Ullakko, IEEE Trans. Magn.,2002, 38, 28142816.
5 M. A. Marioni, R. C. OHandley, S. M. Allen, S. R. Hall, D. I. Paul,M. L. Richard, J. Feuchtwanger, B. W. Peterson, J. M. Chambers andR. Techapoesancharoenkij, J. Magn. Magn. Mater., 2005, 290291,3541.
6 H. E. Karaca, I. Karaman, B. Basaran, Y. I. Chumlyakov andH. J. Maier, Acta Mater., 2006, 54, 233245.
7 S. J. Jeong, K. Inoue, S. Inoue, K. Koterazawa, M. Taya andK. Inoue, Mater. Sci. Eng., A, 2003, 359, 253260.
8 I. Karaman, H. E. Karaca, B. Basarman, D. C. Lagoudas,Y. I. Chumlyakov and H. J. Maier, Scr. Mater., 2006, 55, 403406.
9 H. E. Karaca, I. Karaman, B. Basaran, D. C. Lagoudas,Y. I. Chumlyakov and H. J. Maier,Acta Mater., 2007,55, 42534269.
10 P. J. Webster, K. R. A. Ziebeck, S. L. Town and M. S. Peak, Philos.Mag. B, 1984, 49, 295310.
11 R. Kainuma, H. Nakano and K. Ishida, Metall. Mater. Trans. A,1996, 27A, 41534162.
12 A. Fujita, K. Fukamichi, F. Gejima, R. Kainuma and K. Ishida,Appl. Phys. Lett., 2000, 77, 30543056.
13 K. Oikawa, L. Wulff, T. Iijima, F. Gejima, T. Ohmori, A. Fujita,K. Fukamichi, R. Kainuma and K. Ishida, Appl. Phys. Lett., 2001,79, 32903292.
14 K. Oikawa, T. Ota, F. Gejima, T. Ohmori, R. Kainuma andK. Ishida,Mater. Trans., 2001, 42, 24722475.
15 M. Wuttig, J. Li and C. Craciunescu, Scr. Mater., 2001, 44, 23932397.
16 K. Oikawa, T. Ota, T. Ohmori, Y. Tanaka, H. Morito, A. Fujita,R. Kainuma, K. Fukamichi and K. Ishida, Appl. Phys. Lett., 2002,81, 52015203.
17 H. Morito, K. Oikawa, A. Fujita, K. Fukamichi, R. Kainuma andK. Ishida,Scr. Mater., 2005, 53, 12371240.
18 Y. Sutou, Y. Imano, N. Koeda, T. Omori, R. Kainuma, K. Ishidaand K. Oikawa, Appl. Phys. Lett., 2004, 85, 43584360.
19 C. C. M. Campbell, J. Phys. F, 1975, 5, 19311945.20 T. Kanomata, K. Shirakawa and T. Kaneko, J. Magn. Magn. Mater.,
1987, 65, 7682.21 W. Ito, Y. Imano, R. Kainuma, Y. Sutou, K. Oikawa and K. Ishida,
Metall. Mater. Trans. A, 2007, 38A, 759766.22 K. Oikawa, W. Ito, Y. Imano, Y. Sutou, R. Kainuma, K. Ishida,
S. Okamoto, O. Kitakami and T. Kanomata, Appl. Phys. Lett.,2006, 88, 122507.
23 L. Pal, E. Kren, G. Kadar, P. Szaboand T. Tarnocz,J. Appl. Phys.,1968, 39, 538544.
24 K. A. Gschneidner Jr, V. K. Pecharsky and A. O. Tsokol, Rep. Prog.Phys., 2005, 68, 14791539.
25 R. Kainuma, Y. Imano, W. Ito, Y. Sutou, H. Morito, S. Okamoto,O. Kitakami, K. Oikawa, A. Fujita, T. Kanomata and K. Ishida,Nature, 2006, 439, 957960.
26 P. D. Bogdanoff and B. Fultz,Philos. Mag. B, 2001,81, 299311.27 R. Romero and J. L. Pelegrina, Mater. Sci. Eng., A, 2003,354, 243
250.28 Y. Sutou, N. Kamiya, T. Omori, R. Kainuma and K. Ishida, Appl.
Phys. Lett., 2004, 84, 12751277.29 Y. D. Wang, Y Ren, E. W. Huang, Z. H. Nie, G. Wang, Y. D. Liu,J. N. Deng, L. Zuo, H. Choo, P. K. Liaw and D. E. Brown, Appl.Phys. Lett., 2007, 90, 101917.
30 R. Kainuma, Y. Imano, W. Ito, Y. Sutou, H. Morito, S. Okamoto,O. Kitakami, K. Oikawa, A. Fujita, T. Kanomata and K. Ishida,Appl. Phys. Lett., 2006, 88, 192513.
31 T. Sakon, S. Yamazaki, Y. Kodama, M. Motokawa, T. Kanomata,K. Oikawa, R. Kainuma and K. Ishida, Jpn. J. Appl. Phys., 2007,46, 995998.
32 K. Koyama, H. Okada, K. Watanabe, T. Kanomata, R. Kainuma,W. Ito, K. Oikawa and K. Ishida, Appl. Phys. Lett., 2006,89, 182510.
33 V. K. Sharma, M. K. Chattopadhyay, K. H. B. Shaeb, Anil Chouhanand S. B. Roy, Appl. Phys. Lett., 2006, 89, 222509.
34 B. Zhang, X. X. Zhang, S. Y. Yu, J. L. Chen, Z. X. Cao andG. H. Wu,Appl. Phys. Lett., 2007, 91, 012510.
35 T. Krenke, E. Duman, M. Acet, E. F. Wassermann, X. Moya,
L. Manosa and A. Planes, Nat. Mater., 2005, 4, 450454.36 Z. D. Han, D. H. Wang, C. L. Zhang, S. L. Tang, B. X. Gu and
Y. W. Du, Appl. Phys. Lett., 2006, 89, 182507.37 M. Khan, N. Ali and S. Stadler, J. Appl. Phys., 2007, 101, 053919.
1842 | J. Mater. Chem., 2008, 18, 18371842 This journal is The Royal Society of Chemistry 2008
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