Properties of electrodeposited Co–Mn films: Influence of deposition parameters

Applied Surface Science 358 (2015) 605–611

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Applied Surface Science journal homepage: www.elsevier.com/locate/apsusc

Properties of electrodeposited Co–Mn films: Influence of deposition parameters Ali Karpuz a,∗ , Hakan Kockar b , Mursel Alper c a b c

Physics Department, Kamil Ozdag Science Faculty, Karamanoglu Mehmetbey University, Karaman, Turkey Physics Department, Science & Literature Faculty, Balikesir University, Balikesir, Turkey Physics Department, Science & Literature Faculty, Uludag University, Bursa, Turkey

a r t i c l e

i n f o

Article history: Received 16 March 2015 Received in revised form 14 August 2015 Accepted 21 August 2015 Available online 28 August 2015 Keywords: Co–Mn alloys Electrodeposition Structural characterization Magnetic properties

a b s t r a c t Co–Mn films were produced with electrodeposition considering the deposition parameters of electrolyte pH value, Mn concentration of the electrolyte and film thickness. The effect of each parameter on the structural, magnetic and magnetoresistance properties of the films was studied, separately. X-ray diffraction measurement showed that the films have hexagonal close packed structure. For the films deposited at different pH values, the surface morphologies with different-sized globular granules were observed whereas the morphology covered by uniformly distributed nanoscale grains was detected for the surfaces of all films produced from electrolytes with different Mn concentrations. Also, the ribbed surfaces for 6 ␮m and 4 ␮m, and the nano-sized acicular surface morphologies for 2 ␮m were observed. To the results of magnetic measurements, the saturation magnetization was found to be ∼1230 emu/cm3 for all films deposited at different electrolyte pHs. The highest remanent magnetization value was obtained to be 882 emu/cm3 for the film produced from the electrolyte containing 0.06 M Mn concentration. The coercivity, Hc , values decreased from 147 Oe to 43 Oe when the electrolyte pH decreased from 4.7 to 2.6. And, the Hc continued to decrease from 45 Oe to 31 Oe when the Mn concentration increased from 0.02 M to 0.06 M, and from 27 Oe to 22 Oe when the film thickness decreased from 6 ␮m to 2 ␮m. It is seen that the Hc was immensely affected by the deposition parameters applied during the film production. The Co–Mn films with low Hc were achieved using relatively low electrolyte pH, high Mn concentration of electrolyte and low film thickness, respectively. Also, influence of the deposition parameters affect Hc is in order of the electrolyte pH, the Mn concentration in the electrolyte and the film thickness (from high to low influence). As it is observed that the magnetic properties are sensible to the deposition parameters and the Co–Mn films may have the potential applications in magnetic recording and sensors technologies. © 2015 Elsevier B.V. All rights reserved.

1. Introduction In the recent years magnetic films have been extensively studied [1] since they have many advantages over the applications of magnetic recording and sensor technologies [2]. These films and their alloys can be produced by many techniques including sputtering [3–10], electrodeposition [11], etc. Among them, the electrodeposition of alloys offers many favored deposition advantages. Relatively faster and low cost depositions accompanied by its controllable deposition parameters in production of the films have made it one of the most popular production techniques [12]. In the technique, the properties of films can be affected by many deposition

∗ Corresponding author at: Karamano˘glu Mehmetbey Üniversitesi, Kamil Özda˘g Fen Fakültesi, Fizik Bölümü, Yunus Emre Yerles¸kesi, 70100 Karaman, Turkey. E-mail address: [email protected] (A. Karpuz). http://dx.doi.org/10.1016/j.apsusc.2015.08.179 0169-4332/© 2015 Elsevier B.V. All rights reserved.

parameters such as electrolyte pH, deposition potential, film thickness and electrolyte concentration [13]. Among the ferromagnetic materials, Co-based alloys are promising materials because of their interesting properties [14]. Besides, the investigation of Co–Mn ternary alloy has been an attractive subject since they possess important magnetic properties and application potential in magnetic recording technologies [15–18]. The production of single-crystal Co–Mn alloy on GaAs(0 0 1) has been done by using molecular beam epitaxy [15]. And, the Co–Mn alloys have been commonly produced for solid oxide fuel cell interconnect applications [19–21]. The Mn–Co alloys were also deposited using pulse plating on stainless steel [19] whereas the alloys were produced by DC electrodeposition and the effect of deposition parameters on the film properties was investigated [20]. In the study [21], Wei et al. have produced the Mn–Co oxide coatings and studied their electrical properties and oxidation resistance. The Co–Mn was also used in supercapacitor applications

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Table 1 Experimental parameters applied during the Co–Mn film depositions. Electrolyte pH

Electrolyte composition

Film thickness (±0.1 ␮m)

4.7 3.5 2.6

0.25 M CoSO4 + 0.25 M H3 BO3 + 0.01 M MnSO4

3

2.4 ± 0.1

0.25 M CoSO4 + 0.25 M H3 BO3 + 0.02 M MnSO4 0.25 M CoSO4 + 0.25 M H3 BO3 + 0.03 M MnSO4 0.25 M CoSO4 + 0.25 M H3 BO3 + 0.06 M MnSO4

3

2.3 ± 0.1

0.25 M CoSO4 + 0.25 M H3 BO3 + 0.20 M MnSO4

6 4 2

The bold ones indicate the changed parameters in the each section.

[22,23]. The effect of Co content on properties of Mn–Co oxide electrodes was investigated [22], and the chemical composition and the morphologies of Mn–Ni–Co oxide composites were studied [23]. As seen from the studies on the Co–Mn ternary alloys, in order to better understand the structural and magnetic properties of this material grown by electrodeposition, further investigations are required. Therefore, the study is aimed to investigate the effect of deposition parameters of electrolyte pH value, Mn concentration of the electrolyte and film thickness on the structural and magnetic properties of the electrodeposited Co–Mn films.

and the measurements were performed at room temperature. For the magnetoresistance (MR) measurements, the van der Pauw geometry with four point probes [27] was executed. The applied magnetic field was parallel to the film plane. Additionally, the electric current was in the film plane and applied both parallel and perpendicular to the magnetic field for measurements of longitudinal (LMR) and transverse magnetoresistance (TMR), respectively, as in [28]. The MR ratios were found with the equation given in [2].

2. Experimental

The deposition potential applied for co-deposition of Co and Mn ions was determined using the CV method [29]. The obtained CV curves were presented in Fig. 1 for two different electrolytes

0,05

a) Mn deposition Current (mA)

0

-0,05

-0,1 -2,5

-2

-1,5

-1

-0,5

0

0,5

1

1,5

Voltage (V) 0,5

Co dissolution

b) 0

Current (mA)

The Co–Mn films were deposited with the electrodeposition. The electrolyte was characterized by the cyclic voltammetry (CV) method with a scan rate of 20 mV/s. The CV method was performed using a titanium (Ti) electrode in the cathodic direction from +1.0 V to −2.0 V vs. saturated calomel electrode (SCE). Before electrodeposition of the films, the substrates were polished mechanically with an emery paper and then cleaned with distilled water. The polished substrate surface was covered with an electroplating tape except for deposition area of ∼2.9 cm2 . All films were produced in an electrochemical cell with three electrodes using a computer-controlled potentiostat/galvanostat (EGG model 362) at room temperature (19 ± 1 ◦ C). In the electrochemical cell, while the SCE was preferred as a reference electrode, a polycrystalline Ti plate and a platinum foil were used as a substrate and a counter electrode, respectively. The all potentials were pronounced according to SCE. The thicknesses were calculated during the film deposition with a computer program based on the Faraday’s law [24–26] which has a common use in electrochemical process and they were fixed at specified values in Table 1, separately. The experimental parameters of electrolyte pH, electrolyte composition and film thickness, applied during the Co–Mn film depositions, were shown in Table 1. Besides CoSO4 and MnSO4 , H3 BO3 was used as an additive since it increases the deposition quality by adjusting the pH value and by improving the ions deposition in the electrolyte. After the productions, the films were mechanically peeled off from their substrates and stored in the proper conditions until the characterizations. The film content was detected by the energy dispersive X-ray spectroscopy (EDX, BRUKER). The crystalline structure analysis was made with the X-ray diffraction (XRD, PANalytical) technique with the Cu-K␣ radiation ( = 0.15406 nm). The 2 was scanned between 40◦ and 100◦ for the XRD measurements. The surfaces of the films were observed by the scanning electron microscope (SEM, ZEISS EVO LS 10) at the same time with the EDX measurements. The surface roughness was investigated by the atomic force microscopy (AFM, NanoMagnetics Instruments) to get detailed information about the surface of the films. The magnetic properties were studied with the vibrating sample magnetometer (VSM, ADE technologies DMS-EV9 Model). The applied magnetic field was in the film plane

3. Results and discussion

-0,5

-1 -2,5

-2

-1,5

-1

-0,5

0

0,5

1

1,5

Voltage (V) Fig. 1. The CV curves of two different electrolytes (a) 0.1 M MnSO4 + 0.25 M H3 BO3 (with only Mn) and (b) 0.1 M MnSO4 + 0.25 M H3 BO3 + 0.25 M CoSO4 (with Co and Mn).

A. Karpuz et al. / Applied Surface Science 358 (2015) 605–611

607

Co (100) Co (101) hcp hcp

Intensity (a.u.)

Co (002) hcp

Co (110) hcp

pH 4.7

Co (100) hcp Co (002) Co (101) hcp hcp

Co (100) hcp Co (002) Co (101) hcp hcp

40

50

Co (112) Co (201) hcp hcp

Co (110) hcp Co (112) Co (201) hcp hcp

pH 3.5 Co (110) hcp

Co (112) hcp

pH 2.6 60

70

80

90

100

2 theta (degree) Fig. 2. XRD patterns of the Co–Mn films deposited at different electrolyte pH values.

contain 0.1 M MnSO4 + 0.25 M H3 BO3 (with only Mn) and 0.1 M MnSO4 + 0.25 M H3 BO3 + 0.25 M CoSO4 (with Co and Mn). According to curve of electrolyte with only Mn, see Fig. 1a), the Mn deposition starts at around −1.7 V. The onset value of Co deposition (−0.8 V) has been already detected in our previous study [24]. This value was also confirmed by the other curve obtained from the electrolyte includes both Co and Mn ions, see Fig. 1b). In addition, on the return cycle of this curve, a peak, which starts at around −0.9 V and reaches a maximum at around −0.2 V, can be attributed to the dissolution of Co within the CV results of the study [19]. The presented results show similarities with those of the study [19] in point of the onset of Co, Mn deposition and Co dissolution. As a result, a potential value of −1.9 V is proper for Co and Mn co-deposition because this is a potential value which generates an electrical current in the both electrolytes, separately. Therefore this value was selected as the deposition potential for all films. Fig. 3. SEM images of the Co–Mn films deposited at different electrolyte pH values.

3.1. Effect of electrolyte pH on properties of deposited films According to elemental analysis of the Co–Mn films deposited using the electrolytes have different pH values, the film deposited at high pH value (4.7) consists of 99.5 at.% Co and 0.5 at.% Mn. When the electrolyte pH was gradually decreased from 4.7 to 3.5 and then to 2.6, Co and Mn contents remained at the same values. It was revealed that the decrease in electrolyte pH did not provoke a change in film content. The XRD patterns of the Co–Mn films deposited at different electrolyte pH values are shown in Fig. 2. It is obvious in the figure that all films have the hexagonal close packed (hcp) of Co atoms. The hcp peaks appeared at 2 values of ∼ 41◦ , 45◦ , 47◦ , 76◦ , 93◦ , 95◦ and labeled as (1 0 0), (0 0 2), (1 0 1), (1 1 0), (1 1 2) and (2 0 1), respectively. Besides, some changes occurred in the intensities of the XRD peaks when the electrolyte pH value was changed. As the pH value decreased, the intensity of the peaks (1 0 0), (0 0 2) and especially the intensity of the peak (1 0 1) decreased whereas that of the peak (1 1 0) clearly and gradually increased. While the highest peak was (1 0 1) for the film deposited at high pH value, the (1 1 0) peak was detected as the highest peak for the film deposited at the low pH value. Also, the peak of (2 0 1) disappeared from the XRD pattern as the electrolyte pH decreased. Fig. 3 shows the SEM images of the Co–Mn films deposited at different electrolyte pH values. Electrodeposited film surfaces are sensitive to the electrolyte pH value [30]. The surface of the film grown at the high pH has a structure with numerous grains and their diameter is ∼1 ␮m. When the electrolyte pH gradually

decreased, the diameter of the surface grains decreased in accordance with the decreasing pH value and nano-scaled surface grains were obtained for the film deposited at the low pH value (2.6). The observed grains uniformly dispersed on the surfaces of the all films. Fig. 4 shows the AFM images of the films deposited with different electrolyte pH values. The images prove the SEM images given in Fig. 3 in point of surface grain size and roughness. The surface roughness decreased with the decreasing size of the surface grains. Also, Fig. 4 indicates that the relatively lower stressed surfaces were obtained for the film deposited at the low pH value. It can be emphasized that the electrolyte pH has an important effect on the surfaces of investigated films. Besides, our study has the moderately similar surface morphologies with the study [20] which investigates the effect of different sodium gluconate concentrations at different current densities on the surface morphologies of Mn–Co alloys. In the study, isolated particles were observed on the surfaces of films deposited with electrolyte containing 0.20 M gluconate solution for 100 mA/cm2 and 150 mA/cm2 . The particle size increased with increasing current density. However, some cracks were observed below the isolated particles unlike the present study. The differences in surface morphology are probably due to high amount of manganese and oxygen detected by EDX results of study [20]. The hysteresis loops of the Co–Mn films were illustrated in Fig. 5. As seen in Fig. 5(a), the saturation magnetization, Ms , remained almost at the same value (∼1230 emu/cm3 ). The detected Ms value

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Fig. 4. AFM images of the films deposited at different electrolyte pH values.

1500 pH 2.6 pH 3.5

Magnetization (emu/cm3)

1000

pH 4.7

3.2. Effect of Mn concentration of electrolyte on properties of deposited films

500

0

-500

-1000

-1500 -20

is compatible with that of the Co film of the study [31]. This is an expected result because the Co content (99.5 at.%) of the films investigated in this study and that of the study [31] is almost the same. On the other hand, the Ms value of the film grown at the high pH is slightly lower than the other films. This case can be related to the different-sized globular granules shown in the SEM images. Straumal et al. [32] indicated that the grain size has an important role on Ms of the films. The coercivity, Hc , was also affected by electrolyte pH as shown in Fig. 5(b). The Hc values were found as 147 Oe, 92 Oe and 43 Oe for the electrolyte pH values of 4.7, 3.5 and 2.6, respectively. The decrease of pH value resulted in a considerable reduction of Hc value. This points out to the magnetically smoother films as the electrolyte pH decreases. The decrease in Hc can depend on the changes in the structural properties especially the change in the intensities of the XRD peaks, Since the detected peak intensities in the XRD patterns determine the preferential texture of the films [33,34], and also the Hc are considerably affected by film texture as indicated in studies by Choi et al. [35] and Rahman et al. [36]. In these studies, it was shown that the Hc of the electrodeposited films is mainly affected by the crystallographic texture. In addition, it can be said that the decrease in the size of surface grains seen in Fig. 3 can provoke this decrease of Hc arising from the change of the peak intensities. It can be stated that since the homogeneity and the regularity of the surface appearance increased with the decrease in the size of surface grains (see Figs. 3 and 4), the low stressed surfaces, and hence coatings, were obtained for the films with nano-scaled surface grains. Therefore, the Hc , which is a quite sensitive property to the changes in internal factors of the magnetic materials [37], can be affected by the microstructure such as the size of surface grains. It was indicated [38] that the surface morphology has a significant effect on the Hc values. The remanent magnetization, Mr , was also affected by the electrolyte pH. The change in Mr values is obviously detected in Fig. 5(b). To the results, the Mr values were found to be 509 emu/cm3 , 739 emu/cm3 , 803 emu/cm3 for the films deposited at electrolyte pH values of 4.7, 3.5 and 2.6, respectively. It was seen that the change in the electrolyte pH caused the magnetic properties to change. According to electrolyte pH investigation, the desired film properties, i.e. relatively smoother and lower stressed surfaces in addition to lower Hc values, can be obtained when an strong acidic electrolyte H is preferred for the production of the Co–Mn films, as done in the present study. Fig. 6 shows the MR change of the Co–Mn films deposited at different electrolyte pH values. It was seen that the films exhibited the anisotropic magnetoresistance (AMR) since the LMR increases and the TMR decreases with the increase of magnetic field. Besides, LMR and TMR values slightly increased when the electrolyte pH decreased from 3.5 to 2.6.

-10

0

10

20

Magnetic Field (kOe) Fig. 5. Hysteresis loops of the films deposited at different electrolyte pH values: (a) at high field and (b) at low field.

In order to increase the Mn content of the film, the Mn ions concentration of the electrolyte was increased. Therefore, the Mn concentrations of 0.02 M, 0.03 M and 0.06 M in the electrolyte were considered, respectively, and the other deposition parameters kept constant, as listed in Table 1. It was revealed that the change in the atomic Mn content of the films was found to be ∼1%. The rest of the films were Co atoms. The XRD measurements of the films deposited at different Mn concentrations showed identical patterns. For all patterns, the hcp (1 1 0) peak is the highest peak in the XRD patterns. Besides, the patterns have hcp peaks of (1 0 0), (0 0 2) and (1 1 2). The intensities of these peaks are considerably lower than that of (1 1 0) peak. As an example, the patterns of the films with low (0.02 M) and high (0.06 M) Mn concentration are given in Fig. 7. Unlike the present study, the single-crystal Co0.68 Mn0.32 alloy with a body centered

A. Karpuz et al. / Applied Surface Science 358 (2015) 605–611

609

4

Magnetoresistance (%)

TMR 3,5

pH 3.5

LMR

3 2,5 2 1,5 1 0,5 0 -10

-5

0

5

10

Magnetic Field (kOe)

Magnetoresistance (%)

4

TMR

3,5

pH 2.6

LMR

3 2,5 2 1,5 1 0,5 0 -10

-5

0

5

10

Fig. 8. SEM images of the films produced with low (0.02 M) and high (0.06 M) Mn concentrations.

Magnetic Field (kOe) 1000

Fig. 6. MR change of the Co–Mn films deposited at different electrolyte pH values. 0.02 M Mn 0.03 M Mn

800

0.06 M Mn

Co (110) hcp

3

Co (100) hcp Intensity (a.u.)

Co (002) hcp

Co (112) hcp

0.02 M Mn Co (110) hcp

Co (100) hcp

Magnetization (emu/cm )

600 400 200 0 -200

-150

-100

-50

0

50

100

150

200

-200 -400 -600

Co (002) hcp 40

50

Co (112) hcp

0.06 M Mn 60

70

80

90

100

2 Theta (degree)

-800 -1000

Magnetic field (Oe)

Fig. 7. XRD patterns of the films deposited with 0.02 M and 0.06 M Mn concentrations.

Fig. 9. Hysteresis loops for the films produced using different Mn concentrations of electrolyte.

cubic structure was produced on GaAs(0 0 1) by using the molecular beam epitaxy and the reason for the existence of such a crystal structure was attributed to a critical thickness of ∼13 nm in the study [15]. All films produced considering different Mn concentrations have quite similar morphologies. And, the surfaces are covered by uniformly distributed nanoscale grains. The structure can be easily seen in Fig. 8. In the figure, the SEM images of the films with low (0.02 M) and high (0.06 M) Mn concentrations are shown. The same XRD patterns and surface morphologies are an expected result because the film content, which is mainly determined by the Mn concentration, is the same for all films beside the other important parameters such as the electrolyte pH and film thickness (see Table 1). This case is unlike the other investigated parameter effects in the present study.

Fig. 9 shows the hysteresis loops plotted between ±200 Oe for the films produced at different Mn concentrations of electrolyte. As seen in the figure, the increase of Mn concentration in the electrolyte leads to a decrease in the Hc values. The Hc values were found to be 45 Oe, 38 Oe, 31 Oe for the films deposited with the electrolytes containing 0.02 M, 0.03 M and 0.06 M Mn concentrations, respectively. Almost the same XRD patterns and surface morphologies for the films investigated at low pH and different Mn concentrations clearly revealed that the high concentration of the Mn ions may be the main reason for the decrease in the Hc . The presence of Mn ions probably provoked the deposition of high quality by reducing the internal stress in the films as an additive in the electrolyte and hence caused a decrease in Hc value of the deposits. Based on the results exhibited in Sections 3.1 and 3.2, the decrease in Hc value, which is a desired case, can continue by using high

610

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1000

0.06 M Mn

TMR LMR

3,5

2 micrometers 4 micrometers

3

6 micrometers

800 600

3

Magnetization (emu/cm )

Magnetoresistance (%)

4

2,5 2 1,5 1 0,5 0 -10

-5

0

5

10

Magnetic Field (kOe) Fig. 10. MR change of the film deposited with the electrolyte containing 0.06 M Mn concentration.

400 200 0 -50

-25

-200

0

25

50

-400 -600 -800 -1000

Magnetic field (Oe) Fig. 11. Hysteresis loops of the films produced with different thicknesses.

Mn concentration in the electrolyte besides the low electrolyte pH. However, the presence of Mn ions is a less effective factor than the electrolyte pH for obtaining reduced Hc values since the decrease for different electrolyte pH values is higher than that of the different electrolyte Mn concentrations. Also, it was revealed that the Mr is closely related to the Hc of the films. The Mr values of the films were 736 emu/cm3 , 796 emu/cm3 and 882 emu/cm3 for the films deposited with the electrolytes containing 0.02 M, 0.03 M and 0.06 M Mn concentrations, respectively (see Fig. 9). To magnetic measurements, increase of Mn ions in the electrolyte enhanced the soft magnetic properties for the films. In Fig. 10, the MR change of the film deposited with the electrolyte containing 0.06 M Mn concentration is shown as an example. The films produced at the electrolytes containing different Mn concentrations exhibited the AMR with almost the same ratio. It was calculated that the TMR and LMR ratios were ∼2.5–3% and ∼2–2.5%, respectively.

3.3. Effect of film thickness on properties of deposited films The influence of thickness on properties of films was also studied. The thicknesses of the films were fixed at 6 ␮m, 4 ␮m and 2 ␮m, respectively while the other parameters kept constant. The atomic Mn contents were found to be 1–2% for all films with different thicknesses. The results were found to be compatible with the results found in Sections 3.1 and 3.2. All films with different thickness have the hcp crystalline structure as the rest of the films investigated. Fig. 11 shows the hysteresis loops of the films with different thicknesses. The Hc values were detected to be 27 Oe, 24 Oe and 22 Oe and the Mr values were detected to be 493 emu/cm3 , 561 emu/cm3 and 773 emu/cm3 for the film thicknesses of 6 ␮m, 4 ␮m and 2 ␮m, respectively. A decrease in film thickness resulted in a reduction in Hc values and hence contributed to the soft magnetic properties. The reduction may be due to observed differences in the surface images illustrated in Fig. 12. The study [38] indicates that the Hc of the films can be affected by the surface morphology. The films with 4 ␮m and 6 ␮m thicknesses have the ribbed surfaces. Also, the surfaces were covered by nano-sized globular grains. However, the shape of surface grains varied from this structure to an acicular structure when the film thickness was decreased from 4 ␮m to 2 ␮m. It can be concluded that the low Hc values arise from relatively low thickness values besides the relatively low electrolyte pH and high Mn concentrations. To the results, the relatively thinner films have magnetically smoother properties. However, the film thickness has the lowest effect to reduce the Hc in comparison to electrolyte pH and Mn concentration of the electrolyte because of

Fig. 12. SEM images of surfaces of the films produced with different thicknesses.

A. Karpuz et al. / Applied Surface Science 358 (2015) 605–611

relatively slight reduction in Hc in spite of a considerable decrease in film thickness.

611

acknowledge Selcuk University, Turkey for EDX measurements – SEM micrographs and Karamanoglu Mehmetbey University, Turkey for AFM images.

4. Conclusions References The Co–Mn films were produced considering electrolyte pH value, Mn concentration of the electrolyte and film thickness, separately using the electrodeposition and their structural and magnetic properties were studied to investigate their applications in magnetic recording and sensor technologies. Also, the production parameters were comparatively optimized to get the most efficient film on account of Hc . The hcp structure was detected for the all films whereas the surface morphology varied depending on the deposition parameters. The decrease in the electrolyte pH reduced the size of surface grains from micro-scale to nano-scale. For the films with different thicknesses, the surface morphology varied from a ribbed structure to an acicular structure for decreasing film thickness. The Co–Mn film with low Hc , which is a technologically desired case, was achieved by using relatively low electrolyte pH, high Mn concentration of electrolyte and low film thickness, respectively. In other words, among the investigated deposition parameters, the most important factor for lower Hc is the electrolyte pH. In addition, the presence of the Mn ions in the electrolyte leads to reduced Hc values. The soft magnetic properties were advanced with the decrease of Hc value from 147 Oe to 22 Oe. The Mr values increased with the decrease of electrolyte pH, increase of Mn concentration and decrease of film thickness, separately. Among the films, the film with highest Mr value (882 emu/cm3 ) was obtained from the electrolyte containing 0.06 M Mn concentration. Since the magnetic properties were significantly affected by the deposition parameters, the films may consider as a candidate material in applications of magnetic recording and sensors. Furthermore, the obtained results may be a guide to get comprehensive understanding of the relations between deposition parameters and properties of Co–Mn films. Acknowledgments This work was financially supported by Karamanoglu Mehmetbey University under Grant no. 09-M-13. Also, the work was supported by Balikesir University under Grant no. BAP 2001/02 for MR system, by Uludag University under Grant no. UAP(F)-2010/56, by The Scientific and Technological Research Council of Turkey under Grant no. TBAG-1771 for electrodeposition system, and by State Planning Organization/Turkey under Grant no. 2005K120170 for VSM system. The authors would like to thank M. Haciismailoglu (Uludag University, Turkey) and O. Karaagac (Balikesir University, Turkey) for their contributions in film production and magnetic measurements, respectively, and H. Guler for XRD measurements in Balikesir University, Turkey. They also

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