Electrodeposition and characterization of Fe80Ga20 alloy films

Article abstract of DOI:10.1016/j.electacta.2011.03.046

Due to its high magnetostriction and good mechanical properties Fe ₈₀Ga₂₀ is interesting for magnetostrictive microactuators and sensors. Here we use electrodeposition to grow Fe-Ga films onto Au and Pt coated Si substrates by potentiostatic and pulse potential deposition. Composition, microstructure and structure are analysed. The desired composition of Fe₈₀Ga₂₀ was obtained at -1.4 V_SCE and -1.5 V_SCE, respectively. The origin of low reproducibility and high oxygen content up to 50 at.% is investigated. Optimum deposition conditions to achieve dense, homogeneous films with low oxygen content are identified. In these films the saturation magnetization reaches a maximum value of 1.7 T confirming the high quality of electrodeposited films.

Full text of DOI:10.1016/j.electacta.2011.03.046

Electrochimica Acta 56 (2011) 5178–5183
Contents lists available at ScienceDirect
Electrochimica Acta
journal homepage: www.elsevier.com/locate/electacta
Electrodeposition and characterization of Fe Ga alloy films
8
0
20
a,b,∗
, U. Gaitzsch , S. Oswald , S. Fähler , L. Schultza,b, H. Schlörba
a
a
a
D. Iselt
a
IFW Dresden, Leibniz Institute for Solid State and Materials Research Dresden, PF 27 01 16, 01171 Dresden, Germany
TU Dresden, Faculty of Mechanical Engineering, 01062 Dresden, Germany
b
a r t i c l e i n f o
a b s t r a c t
Article history:
Due to its high magnetostriction and good mechanical properties Fe80Ga20 is interesting for magne-
tostrictive microactuators and sensors. Here we use electrodeposition to grow Fe–Ga films onto Au and
Pt coated Si substrates by potentiostatic and pulse potential deposition. Composition, microstructure
and structure are analysed. The desired composition of Fe80Ga20 was obtained at −1.4 VSCE and −1.5 VSCE,
respectively. The origin of low reproducibility and high oxygen content up to 50 at.% is investigated. Opti-
mum deposition conditions to achieve dense, homogeneous films with low oxygen content are identified.
In these films the saturation magnetization reaches a maximum value of 1.7 T confirming the high quality
of electrodeposited films.
Received 6 December 2010
Received in revised form 8 February 2011
Accepted 11 March 2011
Available online 22 March 2011
Keywords:
Galfenol
Fe100−xGax
Thin film
©
2011 Elsevier Ltd. All rights reserved.
Electrodeposition
Magnetostriction
1
. Introduction
rods. Focusing on smaller dimensions a few groups investigated
the deposition of thin films by physical methods. Butera et al. [18]
deposited 900 nm thin films on (1 0 0)MgO substrates using sputter
deposition, and were able to find the correlation between sputter
pressure and growth behaviour. A linear dependence of the FeGa
lattice parameter was found by Dunlap et al. [19] in 2006: with
increasing Ga content the lattice parameter increases. Wang [20]
analysed the influence of the sputter gas, thermal treatment and
deposition under external magnetic field. Using a sputter pressure
of 1.2 Pa under argon atmosphere he obtained a saturation mag-
netostriction ꢀS of up to 50 ppm. By depositing in a magnetic field
the sample texture changes from (1 1 0) to (1 0 0) orientation. Addi-
tional heat pre-treatment has further improved the soft magnetic
properties. The influence of the partial pressure of the sputtering
Magnetostrictive materials change their dimensions with
changes in magnetization and are therefore interesting for actuator
and sensor applications. Since the discovery of magnetostriction
of iron by James Joule in 1842, intensive research work has been
undertaken to understand the effect [1–5], to increase the length
changes by addition of non-magnetic elements (like Al or rare earth
elements) [2,6–8] and, recently, to use these materials as actua-
tion and sensing devices [9–13]. However, any application requires
besides a high magnetostrictive constant, also good mechanical
properties. Common ferromagnetic metals show good mechani-
cal properties, such as ductility, but the magnetostrictive strain
−
6
−6
is rather low (several 10 × 10
up to 100 × 10 ) [7,14]. Rare
earth alloys show a “giant” magnetostrictive strain in the order
gas on magnetic properties of Fe1
Gax (19 ≤ × ≤ 23) has been
00−x
−
6
of 1000 × 10 (Terfenol-D, Tb0.3Dy0.7Fe ) [5] but they are brittle.
investigated by Javed et al. [4]. Here, the best soft magnetic prop-
erties for sensor applications are obtained when growing at low
sputter pressures of 3 ␮bar. Adolphi et al. [21] investigated the
influence of film thickness and seed layers on the film texture and
consequences of texture on the magnetic properties. They obtained
2
A promising candidate to overcome the mechanical limitations of
rare earth alloys is Galfenol, an alloy of iron and gallium, which
combines mechanical strength (Fe83Ga17 endures tensile stresses
up to 440 MPa with strains approaching 0.25% before failure) [15]
with “large” magnetostrictive strains (up to 400 ppm for quenched
Fe80Ga20 single crystals) [8]. Further advantages are H(sat) < 1 kOe,
a high spontaneous polarization of J = 1.45 T in 1.3 ␮m thick films
S
and summarised that the value of magnetostrictive parameters and
the relative permeability are promising for sensor bending appli-
cations.
Compared to physical methods, electrochemical deposition pro-
vides an easy and low cost method to produce thin films over large
areas, in complex geometries and does not require high vacuum
conditions. However, the electrodeposition of FeGa had been rarely
investigated, since it is hard to deposit Ga [22–24] and its alloys
[25] from aqueous electrolytes. The main reasons for this are the
◦
low temperature dependence in the range from −20 to 80 C [16,17]
and comparatively high oxidation stability. Most of the work on this
material has been done on bulk single crystals, polycrystals and
∗ Corresponding author at: IFW Dresden, Helmholtzstrasse 20, D-01069 Dresden,
Germany. Tel.: +49 351 4659 290; fax: +49 351 4659 500.
E-mail address: d.iselt@ifw-dresden.de (D. Iselt).
0
013-4686/$ – see front matter © 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.electacta.2011.03.046

D. Iselt et al. / Electrochimica Acta 56 (2011) 5178–5183
5179
highly negative standard potential of Ga3+/Ga (E00 = −0.560 V) [23]
and its strong tendency to hydrolyse [24]. McGary reported first
on the electrochemical deposition of Fe–Ga alloys, the fabrication
of nanoscale Galfenol structures [26] and their use as sensor sys-
tems for sonar applications [10]. Using a Watt’s type electrolyte
containing iron(II) and gallium(III) sulphates, boric acid and ascor-
bic acid Fe–Ga nanowire arrays have been deposited into anodic
aluminium oxide templates at a constant potential of −1.36 V.
The Ga content was found to decrease along the length of the
wires and the nanowire arrays were magnetically soft and slightly
anisotropic [26]. However, even for films no crystalline Fe–Ga phase
was observed [10] and no statement was made about the oxygen
content of the deposit. Another group investigated the electro-
chemical fabrication of magnetic multilayered films and nanowire
arrays containing Fe–Ga in order to achieve novel magnetostrictive
behaviour [27,28]. By adjusting both, the electrolyte composition
and deposition potential, Fe78Ga22 films with a crystalline (Fe, Ga)
solid-solution phase were obtained. Multilayered nanowire arrays
were deposited from a single electrolyte by applying different con-
stant potentials. A novel magnetostrictive behaviour was explained
by the formation of twisted spin structures. Very recently, a detailed
study of Fe–Ga codeposition was published by McGary [29]. Using
a Hull cell, where the deposition current density varies across the
cathode, metallic iron, Galfenol, oxide and Ga-rich metal films have
been produced. Complexing the Ga ions with citrate and varying the
3
+
2+
ratio of Ga /Fe ions and the current density allowed to control
the composition as well as grain size and texture of the alloy.
Our present study aims on the preparation and detailed char-
acterization of Fe–Ga alloy films with a gallium concentration of
around 20 at.%. The particular focus is to investigate the origin of the
high oxygen content and to identify appropriate deposition param-
eters for homogeneous, dense alloy films with low oxygen content
that are promising to achieve a high magnetostriction constant.
Fig. 1. (a) Current–potential curves of single element and complete electrolytes on
Au substrates, scan rate 10 mV s−1 and (b) ratio of Ga in potentiostatically deposited
Fe100−xGax films on Au substrates in dependence on the deposition potential.
Cu-K␣ radiation. For magnetic measurements a vibration sample
magnetometer (VSM, Quantum Design PPMS) at 300 K was used.
Hysteresis loops were measured parallel and perpendicular to the
substrate plane using low background signal quartz holders.
2
. Experimental details
Oxidized (1 0 0)Si wafers were coated with either Au or Pt which
3. Results and discussion
acts as working electrodes for the deposition experiments. Based
on McGary’s work [10] the electrolyte consists of an aqueous solu-
tion of 0.3 M FeSO ·7H O, 0.06 M Ga (SO ) ·18H O, 0.5 M boric acid
In order to identify the suitable potential range for the co-
deposition of Fe and Ga potentiodynamic current–potential curves
of both single element and complete electrolytes have been per-
formed, shown in Fig. 1. The cathodic polarization of pure Fe
solution (red dotted curve in Fig. 1a) starts with a first step at
−0.6 V which is attributed to proton reduction. The following
strong current increase, starting at around −1.05 V, represents
the iron reduction overlapped by water decomposition. The
current–potential curve of the pure Ga3+ solution (blue dashed
curve in Fig. 1a) is characterized by a continuous current increase
starting at −0.7 V. The first step observed in Fe solution does not
occur, pointing out the inhibition of proton reduction. This, as well
as the much smaller slope compared to the Fe2+ solution, might be
explained by a passivation of the electrode surface by hydrolysis
products of Ga. The starting point of Ga3+ reduction cannot be iden-
tified because of its potential overlapping with the one for water
decomposition. The behaviour of the complete electrolyte (black
solid curve in Fig. 1a) is similar to the Ga3+ solution down to −0.95 V.
Afterwards a two step behaviour is observed that approaches the
current density of the iron solution at potentials around −2.0 V.
Potentiostatic deposition experiments from the single element
solutions provide stable films at potentials E ≤ −1.0 V for iron and
E ≤ −1.8 V for Ga, in contrast to the results reported by Flamini
et al. [24] who quote the suitable deposition potential for Ga
as E ≤ −1.58 V. Potentiostatically deposited films from the com-
plete electrolyte are unstable at potentials more positive than
−1.3 V, dissolving immediately under gas evolution after stopping
4
2
2
4
3
2
(
H BO ) as a buffer and 0.04 M ascorbic acid (C H O ) as an antiox-
3 3 6 8 6
idant agent, where the pH was adjusted to 1.5 by adding sulphuric
acid. For each experiment 20 ml of fresh electrolyte was used. All
deposition experiments were performed at room temperature in
a three electrode arrangement placed in a Teflon cell. A Pt sheet
was used as the counter electrode and a Saturated Calomel Elec-
trode (SCE) as reference electrode. The electrode potentials all refer
to the potential of the SCE (−241 mVSHE). Deposition experiments
were carried out using an EG&G Potentiostat/Galvanostat Model
2+
2
63A.
Sample surface and cross sectional morphologies as well as
film thickness were examined using high-resolution scanning elec-
tron microscopy (HR-SEM Leo 1530 Gemini, Zeiss) and focused
ion beam technique (FIB, Zeiss Cross Beam 1540XB), respectively.
The integral composition was obtained by energy dispersive X-ray
spectroscopy (EDX, Leo 1530 Gemini, Zeiss with Si(Li)-detector).
To estimate the oxygen content and the detailed oxygen binding
behaviour depth profiles were measured by Auger electron spec-
troscopy (AES, PHI Model 660 Scanning Auger Microprobe, Physical
Electronics) and X-ray Photoelectron Spectroscopy (XPS, PHI 5600
CI, Physical Electronics, Excitation: Mg-K␣ radiation, sputtering:
+
Ar -ions 3.5 keV, 3 nm/min sputter abrasion). The structure was
analysed by X-ray diffraction in Bragg–Brentano geometry (XRD,
Phillips PW 3400, Co-K␣ radiation) and the texture by pole figure
measurements using a Philips X‘Pert 108 Texture Goniometer with

5
180
D. Iselt et al. / Electrochimica Acta 56 (2011) 5178–5183
Fig. 2. SEM surface image (a) and FIB cross section (b) of a E1 = −1.5 V, E2 = −0.9 V (t1 = t2 = 10 s) pulse-deposited Fe80Ga20 film.
Fig. 3. FIB cross sections of pulse-deposited Fe–Ga films at different pre-conditions: (a) deposition started 1200 s after immersing electrode into electrolyte and (b) immersing
electrode into electrolyte under potential applied.
sequent strong interactions of the amphoteric Ga3+ ions and/or its
hydrolysis products with the substrate surface. The detailed reduc-
tion mechanism is beyond the scope of this article and will be the
subject of a further study.
Potentiostatically deposited films were hardly reproducible
showing irregular morphologies and oxygen contents of up to
50 at.% as determined by SEM/EDX. Both, the inhomogeneous mor-
phology and the high oxygen content were expected to be avoided
by applying appropriate potential pulses. While keeping the depo-
the deposition. However, at E = −1.3 V and lower potentials stable
films are obtained. As shown in Fig. 1b the Ga ratio in Fe1 Gax
00−x
increases to a maximum value of around 50 at.% with decreasing
potential but with high uncertainty due to film inhomogeneities
caused by a strong hydrogen evolution. The desired composition
of about Fe80Ga20 is obtained at −1.3 V ≤ E ≤ −1.4 V with compara-
tively minor changes.
For all following depositions the substrate was changed from Au
to Pt. This allows later X-ray diffraction analysis of the crystalline
structure of the deposited films by avoiding the overlap of substrate
and film reflections. To achieve the desired composition of Fe80Ga20
on Pt an offset of the deposition potential to −1.5 V was essen-
tial. This potential offset is obviously associated with the catalytic
activity of the Pt substrate, enhancing proton reduction and sub-
sition potential constant (E = −1.5 V) a second “off”-potential
1
E = −0.9 V was introduced and both potentials were applied 60
2
times for t = t = 10 s. SEM analysis reveals an almost smooth sur-
1
2
face morphology with a high number of large grains growing out
of the film (see Fig. 2a). FIB cross sections (Fig. 2b) show a dense
Fig. 4. XPS depth profiles of pulse-deposited Fe–Ga films at different pre-conditions: (a) deposition started 1200 s after immersing electrode into electrolyte and (b) immersing
electrode into electrolyte under applied potential.

D. Iselt et al. / Electrochimica Acta 56 (2011) 5178–5183
5181
Fig. 5. XPS spectra of iron (a and b) and gallium (c and d) at different sputter depth (marked in Fig. 4): (a) and (c) deposition started 1200 s after immersing electrode into
electrolyte and (b) and (d) immersing electrode into electrolyte under applied potential.
layer with compact particles. At the bottom of each particle pores
were observed that are most probably originate from gas bubbles
evolved at the initial stages of deposition.
Aiming at homogeneous, dense films without outgrowing par-
ticles these pores have to be avoided. This again requires further
investigation of the initial stages of deposition. To do this two bor-
der cases have been intensively investigated: (A) the deposition
potential is applied 1200 s after immersing the working electrode
into the electrolyte and (B) the working electrode is immersed to
the electrolyte under applied deposition potential.
mated as 85:15 in reasonable agreement with the EDX data given
above. The deviation of ∼7 at.% might be related to the sum of the
systematic errors (use of standard sensitivity factors, preferential
sputtering) of both methods. The increase of the Pt and later the Si
signal indicates that the substrate surface is reached.
In general, the XPS profiles show a high oxygen content of
20–30 at.% for sample (A) and a much lower oxygen content of
1–10 at.% for sample (B). Directly at the sample surface both sam-
ples show a high oxygen content up to 80 at.% indicating a strong
affinity to surface oxidation. Afterwards both samples strongly dif-
fer from each other. The oxygen content in sample (A) only slowly
reduces to a relatively high minimum value of 20 at.%. The most
probable reason for this slow decrease is the high porosity and
therefore high surface-to-volume ratio observed in the cross sec-
tion (Fig. 3a). With increasing sputter depth the oxygen content
again increases up to 30 at.%. In the lower third of the film thick-
ness the oxygen content again slightly decreases to a final value
of around 28 at.%. Due to the high porosity of the film oxygen sur-
face diffusion might be strongly enhanced therefore influencing the
accuracy of the results.
Whereas the Fe/Ga atomic ratio of both films is identical at ∼0.78
the overall thickness of film (A) with ∼400 nm exceeds the thick-
ness of film (B) with ∼200 nm by almost a factor of 2. Furthermore,
FIB cross sections reveal strong differences in film morphology
(
Fig. 3). An inhomogeneous, porous and dendritic like growth in
three different stages is observed for sample (A) (Fig. 3a). Sample (B)
Fig. 3b) is a dense and homogeneous film without any pores. Here,
(
grain like contrasts can be seen in the FIB cross section indicating
a metallic deposit.
In order to analyse the oxygen content and its distribution over
film thickness in more detail AES and XPS depth profiles have
been measured. The related XPS profiles starting from the film sur-
face down to the film–substrate interface of samples (A) and (B)
are compared in Fig. 4a and b, respectively. Similar results were
obtained by AES depth profiles measurements and therefore are not
shown here. For both samples the Fe:Ga atomic ratio can be esti-
Contrary, the oxygen content in sample (B) sharply decreases to
less than 1 at.% within the first 20 nm (4–6 min sputter depth). This
value remains constant over 2/3 of the film thickness and slightly
increases to 11 at.% near the film–substrate interface.
Detailed information about the oxygen binding behaviour was
extracted from single spectra recorded during the XPS depth profile

5
182
D. Iselt et al. / Electrochimica Acta 56 (2011) 5178–5183
measurements. For both, iron and gallium characteristic selected
spectra over the thickness of the films are shown in Fig. 5. The
selected depth steps for both samples are marked in Fig. 4 with
numbers from 1 to 5. As expected from the very high oxygen con-
tent both iron and gallium are oxidized at the sample surfaces. No
metallic Fe and Ga had been determined in spectrum 1 for both
samples.
For the porous and inhomogeneous sample (A) the oxygen con-
tent decreases only slowly (see Fig. 4a) and therefore oxidized
species still appear in spectra 2 of Fig. 5a and c. Unlike Ga that is still
completely oxidized metallic Fe already arises. The Fe spectra 3–5
(
Fig. 5a) show mostly metallic Fe and only a minor fraction of oxi-
dized Fe species. Spectrum 3 of Ga (Fig. 5c) shows mainly metallic
gallium with a minor portion of oxidized Ga whereas this trend is
again reversed in spectra 4 and 5 with more oxidized than metallic
Ga.
In contrast to these results the spectra 2–5 of the dense and
homogeneous sample (B) show nearly pure metallic peaks for both
iron (Fig. 5b) and gallium (Fig. 5d) over the whole film thickness.
No trace of oxidized species is observed in spectra 2–4 in agree-
ment with the low oxygen content of only about 1 at.% found in
this region. Spectrum 5 of gallium near the interface to the sub-
strate (Fig. 5d) reveals a slight decrease of the metallic quantity
and a marginal shoulder of oxidized Ga shows up.
Fig. 6. XRD pattern (a) and (1 1 0) pole figure (b) of a dense, homogeneous film.
Substrate reflections in the XRD pattern are marked with (*).
Even though the particular deposition mechanism is not known
in detail, the combination of the obtained results gives important
hints for the process occurring: strong interactions of the elec-
trolyte components, mainly Ga3+ ions or its hydrolysis products,
with the Pt substrate lead to the formation of a passivating film at
the interface between electrolyte and substrate. Once a passivating
film is formed electrodeposition can occur only at defects in this
film or at high overpotentials favoring dendritic growth as well as
hydrogen evolution and the formation of highly porous films with
high surface area. After terminating the deposition the high sur-
face area immediately tends to form a surface oxide layer. On the
other hand, if the deposition is immediately started once the elec-
trolyte comes into contact with the substrate, these interactions are
almost completely prevented. Thereby avoiding strong passivation
can prevent both dendritic growth and high oxygen content. As
a result dense films with oxygen contents as low as 1 at.% can be
obtained that are required for magnetostrictive applications.
The XRD pattern of the homogeneous, dense sample is pre-
Fig. 7. Hysteresis loops of a dense layer with low oxygen content measured parallel
(||) and perpendicular (⊥) to the substrate.
◦
sented in Fig. 6a. Besides the substrate reflection of Si(82 ) and
◦
◦
◦
Pt(46 , 104 ) only one intense reflection at 52.1 occurs that can be
assigned to the (1 1 0) reflection of the thermodynamically stable
is required to saturate the field out of plane. Close to saturation in
both directions a noticeable curve bending is observed. This indi-
cates the presence of some additional anisotropy, which may either
originate from magnetocrystalline anisotropy or, more likely, on
magnetostrictive anisotropy induced by film stress.
The magnetic measurements particularly confirm the high qual-
ity of the electrodeposited films containing only a negligible
number of defects and impurity phases.
␣
-Fe Ga phase exhibiting a disordered bcc structure. A very weak
3
◦
reflection related to (2 1 1) Fe Ga is additionally observed at 98.4 .
3
As the (1 0 0) and (2 0 0) reflections of Fe Ga are absent these results
3
indicate a strongly preferred (1 1 0) orientation. Additional texture
measurements of the (1 1 0) pole figure (see Fig. 6b) show an intense
◦
◦
central spot at ꢁ < 10 and a ring at ꢁ = 60 . The angle between the
◦
different {1 1 0} planes in the cubic system is 60 . Therefore the
◦
ring at 60 with equally distributed intensities combined with the
4. Conclusion
central spot proves a (1 1 0) fibre texture with no preferred in plane
orientation. Additionally measured (2 0 0) and (2 1 1) poles confirm
the (1 1 0) fibre texture (not shown).
FeGa alloy films with a desired composition close to Fe80Ga20
and a (1 1 0) Fe Ga fibre texture have been fabricated electrochem-
Magnetic properties have been obtained by measuring hys-
teresis loops parallel and perpendicular to the film plane and are
shown for the dense film with low oxygen content in Fig. 7. The
film shows a low coercivity of 4 mT parallel and 30 mT perpendic-
ular to the substrate indicating soft magnetic behaviour. A high
saturation magnetization of about 1.7 T is achieved that exceeds
values reported for sputtered films of 1.45 T [21] and approaches
the values for bulk single crystals of 1.75 T [2]. As expected due to
shape anisotropy the easy axis of magnetization is strongly aligned
within the film plane and a field close to spontaneous polarisation
3
ically. Strong interactions of the electrolyte with the substrate
surface are identified to cause low reproducibility and high oxygen
content. Using optimized pre-treatment and pulsed potential con-
ditions the films are dense and homogeneous. The oxygen content
was reduced to less than 1 at.% and the saturation magnetization
reaches up to 1.7 T, confirming the high quality of these films. These
results show that electrodeposition can be most effectively used to
grow Fe80Ga20 films for application in magnetostrictive actuating
and sensing devices

D. Iselt et al. / Electrochimica Acta 56 (2011) 5178–5183
5183
Acknowledgement
[13] P.R. Downey, A.B. Flatau, P.D. McGary, B.J.H. Stadler, Proc. SPIE 6932 (2008)
9320P.
6
[
[
14] S. Armyanov, Electrochim. Acta 45 (2000) 3323–3335.
15] T.A. Lograsso, A.R. Ross, D.L. Schlagel, A.E. Clark, M. Wun-Fogle, J. Alloys Compd.
The authors thank K. Hennig for FIB investigations.
References
305 (2003) 95–101.
[
[
16] J.R. Cullen, A.E. Clark, M. Wun-Fogle, J.B. Restorff, T.A. Lograsso, J. Magn. Magn.
Mater. 226 (2001) 948–949.
17] R.A. Kellogg, A.M. Russell, T.A. Lograsso, A.B. Flatau, A.E. Clark, M. Wun-Fogle,
Acta Mater. 52 (2004) 5043–5050.
18] A. Butera, J. Gómez, J.A. Barnard, J.L. Weston, Physica B 384 (2006) 262–264.
19] R.A. Dunlap, J.D. McGraw, S.P. Farrell, J. Magn. Magn. Mater. 305 (2006)
[
[
1] B.D. Cullity, C.D. Graham, Introduction to Magnetic Materials, John Wiley and
Sons Inc., NJ, 2009.
2] A.E. Clark, M. Wun-Fogle, J.B. Restorff, K.W. Dennis, T.A. Lograsso, R.W. McCal-
lum, J. Appl. Phys. 97 (2005) 10M316.
[
[
3
15–320.
20] B.W. Wang, S.Y. Li, Y. Zhou, W.M. Huang, S.Y. Cao, J. Magn. Magn. Mater. 320
2008) 769–773.
[
[
[
3] E.M. Summers, T.A. Lograsso, M. Wun-Fogle, J. Mater. Sci. 42 (2007) 9582–9594.
4] A. Javed, N.A. Morley, M.R.J. Gibbs, J. Magn. Magn. Mater. 321 (2009) 2877–2882.
5] C. Mudivarthi, M. Laver, J. Cullen, A.B. Flatau, M. Wuttig, J. Appl. Phys. 107 (9)
[
[
(
21] B. Adolphi, J. McCord, M. Bertram, C.-G. Oertel, U. Merkel, U. Marschner, R.
Schäfer, C. Wenzel, W.-J. Fischer, Smart Mater. Struct. 19 (2010) 055013.
22] E. Reichel, Fresenius J. Anal. Chem. 87 (1932) 321–332.
23] W.M. Saltman, N.H. Nachtrieb, J. Electrochem. Soc. 100 (1953) 126–130.
24] D.O. Flamini, S.B. Saidman, J.B. Bessone, J. Appl. Electrochem. 37 (2007)
(
2010) A957.
[
[
[
6] R.C. Hall, J. Appl. Phys. 30 (1959) 816–819.
7] R.C. Hall, J. Appl. Phys. 31 (1960) 1037–1038.
8] A.E. Clark, J.B. Restorff, M. Wun-Fogle, T.A. Lograsso, D.L. Schlagel, IEEE Trans.
Magn. 36I (2000) 3238–3240.
[
[
[
467–471.
[9] R.R. Basantkumar, B.J.H. Stadler, W.P. Robbins, E.M. Summers, IEEE Trans. Magn.
[
[
[
[
25] A. Brenner, Electrodeposition of Alloys, Academic Press Inc., NY, 1963.
26] P.D. McGary, B.J.H. Stadler, J. Appl. Phys. 97 (2005) 10R503.
27] N. Lupu, H. Chiriac, P. Pascariu, J. Appl. Phys. 103 (07) (2008) B511.
28] N. Lupu, P. Pascariu, C. Gherasim, H. Chiriac, IEEE Trans. Magn. 44 (2008)
4
2 (2006) 3102–3104.
[10] P.D. McGary, L.W. Tan, J. Zou, B.J.H. Stadler, P.R. Downey, A.B. Flatau, J. Appl.
Phys. 99 (2006) 308–310.
[
[
11] H.M. Schurter, Y. Zhang, R. Wu, A.B. Flatau, Proc. SPIE 7289 (2009) 72891Y.
12] C. Wenzel, B. Adolphi, U. Merkel, A. Jahn, U. Marschner, J. Ziske, H. Neubert,
W.-J. Fischer, Sens. Actuators A 156 (2009) 129–133.
3
005–3008.
29] P.D. McGary, K.S.M. Reddy, G.D. Haugstad, B.J.H. Stadler, J. Electrochem. Soc.
57 (2010) D656–D665.
[
1