8. electrodeposition of nanocrystalline nickel by using rotating cylindrical electrodes

8/10/2019 8. Electrodeposition of Nanocrystalline Nickel by Using Rotating Cylindrical Electrodes

1/6

Materials Chemistry and Physics 111 (2008) 469474

Contents lists available atScienceDirect

Materials Chemistry and Physics

j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / m a t c h e m p h y s

Electrodeposition of nanocrystalline nickel by using rotating

cylindrical electrodes

E. Moti, M.H. Shariat , M.E. Bahrololoom

Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz 7134815939, Iran

a r t i c l e i n f o

Article history:

Received 27 December 2006

Received in revised form 24 April 2008

Accepted 30 April 2008

Keywords:

Nanocrystalline

Nickel

Electrodeposition

Rotating cylindrical electrode

Hardness

a b s t r a c t

In thisresearch, nanocrystalline nickel (1425nm) waselectrodeposited on rotatingcylindrical electrodesin a modified Watts bath. Saccharin was used as a grain refiner. The effect of cathode rotation speed and

saccharin concentration on the grain size was studied by transmission electron microscopy (TEM) andX-

ray diffraction (XRD) analysis. The preferred orientation of deposits progressively changed from a (2 2 0),

(2 0 0), and (11 1) fiber texture for a saccharin free bath to a (1 1 1) and (20 0) double fiber texture for

a bath containing 5 g l1 saccharin. Cathode rotation enhanced the intensity of (1 1 1) peak relative to

(1 0 0). The effect of cathode rotation speed, current density, and saccharin concentration on the coating

microhardness was investigated. The maximum recorded hardness was 620 HV for 14 nm grain size. The

effect of current density and saccharin concentration on morphology was observed by scanning electron

microscopy (SEM). The current efficiency changes were studied as a result of saccharin concentration.

2008 Elsevier B.V. All rights reserved.

1. Introduction

Nanostructural materials exhibit different mechanical, physical,

and chemical properties relative to conventional structures[13].

Therefore, in the last two decades much interest has been directed

to them. This group of materials often is identified by a physical

dimension (such as grain size) 1100 nm and a significant amount

of surfaces and interfaces. Nanostructure materials can be made by

bottom-up approaches like inert gas condensation, chemical meth-

ods, and electrodeposition or top-down methods like ball milling,

mechanical alloying, and severe plastic deformation [4]. In con-

trast with other methods, electrodeposition presents economical

and technological advantages[5].Accordingly, many efforts have

been made in order to synthesize nanocrystalline Ni [6], Co [7],

Zn[8], NiCo[9], NiB[10], NiZn[11], NiWC [12], and NiSiC

[13].

The investigated properties of nanocrystalline (nc) nickel shows

unique or improved properties as compared to conventional poly-

crystalline nickel. The hardness of nc nickel has been reported to

be640HV at14nm grain size [14]. Furthermore, a notable increase

in ultimate tensile stress (1390MPa) was observed for nc nickel

(40nm)[15].The wear rate of nc nickel with an average grain size

13 nmis abouthalf ofthe wear ratein polycrystallinenickel (90m)

[16]. Hydrogen transportation rate and storage capacity in nc nickel

Corresponding author.

E-mail address: [email protected](M.H. Shariat).

have been previously shown to be significantly higher than those

observed in conventional materials[17]. In addition, a higher elec-

tro catalytic behavior has been noted with regard to hydrogen

evolution reaction (HER) for alkaline water electrolysis at room

temperature [17]. The improved corrosion and fatigue properties

have also been reported for nc nickel[18,19].

In electrodeposition of nc materials like other bottom-up meth-

ods, nucleation and growth are in competition to determine grain

size. Therefore, low growth rate and high nucleation rate for syn-

thesis of nc materials are unavoidable. In some researches grain

refiners like saccharin [20], coumarine [21], thiourea [21], and

formic acid [22] havebeen successfully applied to achieve nc nickel.

These organic additives affect surface diffusion of adion on the

growth surface and decrease growth rate. On the other hand, such

additives increase the cathodic overpotential [23]. Consequently,

based on the classical theories on electrochemical phase forma-

tion and growth[24], the nucleation rate is increased. At the same

time problems like hydrogen evolution is probable. For control-

ling such problems, pulse current [25], rotating electrodes [15],

and anti-pitting agents [15] have been used. Therefore, in all of

the mentioned methods for deposition nanocrystalline materials in

additionto grain refining,deteriorating effects of high overpotential

must be prevented.

The main goal of this work is to combine advantages of saccha-

rin addition as a grain refiner and a rotating cylindrical electrode

to produce nc nickel. The effect of saccharin concentration on grain

size, texture, hardness, current efficiency, and morphology will be

discussed. The relation between cathode rotation speed and grain

0254-0584/$ see front matter 2008 Elsevier B.V. All rights reserved.

doi:10.1016/j.matchemphys.2008.04.051
http://www.sciencedirect.com/science/journal/02540584mailto:[email protected]://localhost/var/www/apps/conversion/tmp/scratch_1/dx.doi.org/10.1016/j.matchemphys.2008.04.051http://localhost/var/www/apps/conversion/tmp/scratch_1/dx.doi.org/10.1016/j.matchemphys.2008.04.051mailto:[email protected]://www.sciencedirect.com/science/journal/02540584


2/6

470 E. Moti et al. / Materials Chemistry and Physics 111 (2008) 469474

Fig. 1. Scanning electron microscopy micrographs (a) 2 A dm2, 500 rpm, without saccharin addition (b) 2 A dm2, 500 rpm, saccharin concentration 5 g l1 , (c) 6A dm2 ,

500 rpm, saccharin concentration 5 g l1, and (d) microhardness indentation effects (electrodeposition conditions were similar to those ofFig. 1b).

size and hardness is noticed. In addition, the effect of current

density on the hardness and morphology of nc nickel is also

reported.

2. Experimental

Cylindrical copper cathodes each having a surface area of 10 cm2 and 1.9cm

diameter, were utilized as substrates for electrodeposition of nc nickel (35100m

thickness) using direct current and 0800 rpm rotation speed. A Watts bath (all

analytical grade chemical)was used containing NiSO4 6H2O(300gl1), NiCl26H2O

(45gl1), H3BO3 (45gl1), saccharin (05g l1) as grain refiner, and sodium lauryl

sulfate (0.25g l1) as an anti-pitting agent. The bath temperature was adjusted at

601 C. Before plating,the substrates were degreased withacetoneand thenelec-

tropolished by dipping into a solution containing 25 vol% phosphoric acid (33 wt%),

25vol% ethanol alcohol (99vol%), and 50vol% distilled water while applying a

1015 A dm2 currentdensity for1 min. Two nickelsheet (totalsurfacearea 25cm2)

anodes were fixed on two sides of cathode at 2 cm distance. The pH was 2, and it

was kept constant by adding a mixture of H2SO4:HCl (7:1). The electrolytes were

replaced after coating five specimens.

The deposit microstructures were characterized by D8 Bruker X-ray diffraction

(XRD) and the X-ray scan rate was 0.05 s1/with Cu K radiation (= 0.15405nm).

Thegrain sizewas determined for X-ray peak broadeningsby applying Scherrerfor-

mula for (10 0) reflections[26].The peak broadenings were measured by integralwidth method [26]and corrected for instrumental peak broadening using a full-

annealed nickel (at 600 C for 24 h) by Jones equation[26]. To verify the accuracy of

the grain size measurements, some specimens were also examined in a C.M. 200-

S.E.G. Philips scanning transmission electron microscope (STEM). For making TEM

specimens, the nc nickel deposit were separated from their substrates by immer-

sion in an aqueous solution containing CrO3 (250g l1) and (98wt%) sulfuric acid

(20mll1). Then samples were prepared by jet polishing with a 10 vol% perchloric

acid, 15vol% acetic acid, and 75 vol% methanol electrolyte at 20 C and an applied

voltage of 20 V. The grain size of nanocrystalline nickel was determined directly

from dark-field and bright-field transmission electron micrographs by measuring

120 grains.

Morphological studies of deposits were carried out by using an Oxford Instru-

ment Stereoscan 120 scanning electron microscope (SEM). Microhardness of nickel

deposits were measured by using a Wetzier Pietz microhardness tester with a Vick-

ersindenter.The microhardnesstestswerebased on E 384-89ASTMand theapplied

loadwas25 g foran indentation timeof 15s. Becauseof thecylindricalshapeof spec-

imens and omitting the effect of substrate on microhardness, all the microhardness

tests were carried out on the cross section of coatings. The current efficiency was

calculated from the charges passed and the weight gained by applying Faradays

equation.

3. Results and discussion

Fig. 1ashows the morphology of nickel deposited at 2 A dm2

and 500 rpm without saccharin addition. Such morphology was

related to structures with grain size in micrometer range[27].This

deposit exhibits a relatively large surface roughness. Consequently,

diffuse light reflection gives it a dull appearance [28]. Saccharin

addition (5 g l1) changed the morphology of deposit (Fig. 1b). In

addition to inhibition of pyramidal growth because of saccharin

addition [29], the uniform current distribution in rotating cylindri-

cal electrode[30]promoted the leveling. As a result of leveling a

very smooth surface was observed. For this reason as also reported

elsewhere[28],the appearance of nc nickel was mirror-like. Such

results were also observed by Qu et al. [31],Erb and El-Sherik[7].

In contrast toFig. 1b, the destructive effects of increasing current

density from 2 to 6Adm

2 is shown in Fig. 1c. Clearly, blistersare observed and they can be as a result of adsorbed hydrogen.

Because of hydrogen adsorption or hydrogen evolution, pH can

locally increase. Therefore, black areas in Fig. 1c may be nickel

hydroxide. Fig. 1d shows the Vickers microindentation effect on

the cross section of copper substrate (the greater lozenge in the

lower part ofFig. 1d) and nc nickel coating (the smaller lozenge in

upper part ofFig. 1d). The measured microhardness for copper is

908 HV and for nc nickel is 62025HV.

The effect of saccharin concentration on the preferred orien-

tation of nickel deposits is shown in Fig. 2. For microcrystalline

nickel the orientation with significant (2 2 0), (2 0 0), and (1 1 1)

reflection are exhibited in Fig. 2a. In accord with this random

grainorientation,the surface morphology of microcrystalline nickel

(Fig. 1a) does not exhibit the regular symmetry. However, the pre-


3/6

E. Moti et al. / Materials Chemistry and Physics 111 (2008) 469474 471

Fig. 2. X-ray diffraction patternfor nickel at differentsaccharin concentration (a) 0,

(b) 0.25, (c) 1, (d) 3 and (e) 5g l1, 500rpm, 2Adm2.

ferred orientated in the (1 1 1) plate direction was reported for

microcrystalline nickel [32]. This difference can be a result of

cathode rotation in this research. Increasing saccharin concen-

tration changes the preferred orientation from a (22 0), (2 0 0),

and (11 1) to (11 1) (2 00) double fiber texture (Fig. 2be).

This is consistent with findings reported by El-Sherik and

Erb [6]. Some researchers related this phenomenon to the decrease

in grain size, crystallographically anisotropy, surface energy, and

nucleation rate [33]. In addition, as a result of thinner coating(32m) X-ray reflection, marked S, originating from substrate, can

also be seen in Fig. 2e. The effect of saccharin concentration on

the line broadening of (1 1 1) reflection was presented inFig. 3.

The average grain size value of nickel deposited at saccharin con-

centration 1, 3, and 5 g l1 calculated from the (1 1 1) lines of f.c.c.

nickel according to Scherrer formula were 28, 18, and 14 nm. The

results of calculation are invalid for (11 1) lines broadening in sac-

charin concentration 0 and 0.25g l1, because the measured line

broadenings approximately are equal to the instrumental error

(0.0043188 rad).

X-ray diffractograms measured at different cathode rotation

speed for 2Adm2 and 5 gl1 saccharin are shown in Fig. 4.

Textural changes were observed in Fig. 4. The intensity ratio

RI= I(200)/I(1 1 1) is decreased by increasing the cathode rotation

Fig. 3. (1 1 1) X-ray diffraction peaks of nickel at different saccharin concentration,

(a) 0, (b) 0.25, (c) 1, (d) 3 and (e) 5g l1, 500rpm, 2Adm2.

speed. It can be related to more adsorption of saccharin ion or

atomic hydrogen on the cathode surface during electrodeposition.

The textural organization of deposits has been attributed to the

existence or formation of different chemical species on the cath-

ode surface during the cathodic process. It was reported that nickel

deposits in the presence of organic additives denoted (1 1 1) tex-

ture or an apparently random orientation [34].In addition, it was

reported that by using the rotating electrode hydrogen adsorp-

tion on the cathode is increased and it in turn inhibits growth

for (2 0 0) direction [35]. Both of these results have a good con-sistency with the XRD results in this work. The calculated grain

sizes of deposits are mentioned in Fig. 4. Grain sizes of deposit

produced by the rotating electrode are smaller than that of the

deposit of stationary electrode. It can be related to the better sac-

charin adsorption on the rotating electrode. On the other hand,

grain size at 800 rpm is larger than grain size at 500 rpm. This may

be a result of small hydrogen ion adsorption instead of large sac-

charin ion adsorption in high shear force on the cathode surface

at high cathode rotation speed. Similar conclusions deduced from

the literatures [6,35], although hydrogen adsorption can noticeably

change the texture, it does not affect the grain size like saccha-

rin.

Fig. 5ac shows planer bright-field and dark-field STEM micro-

graphs for a nickel deposit, which was produced from a bath


4/6


Fig. 4. X-ray diffraction pattern for nickel at different cathode rotation speed (a)

stationary cathode, (b) 500 and (c) 800 rpm at 5 g l1

saccharin concentration and2 A dm2.

containing 5 g l1 saccharin, 2 A dm2 current density and 500rpm

rotationspeed. Thegrainsize distributionwas shown inFig.5d. The

grain size distribution is in the range 825 nm, and the determined

average grain size was 13.5nm, which was in good agreement with

XRD results. This consistency implies that the XRD technique is

a suitable method to characterize the grain size of nc nickel in

this study. Like the planer micrographs of nc nickel, which was

electrodeposited by DC current technique[14]the equiaxed grain

structure were observed, as shown in the TEM micrographs of

Fig. 5.Such microstructures have been reported by El-Sherik and

Erb[6].Fig. 6 shows the effect of cathode rotation speed on micro-

hardness and the grain size of nickel coatings at 2 A dm2 and

5 g l1 saccharin concentration. The increase in microhardness

was observed with increase in cathode rotation speed from 0

to 500rpm. On the other hand, in the cathode rotation speed

more than 500 rpm the decrease in microhardness was shown.

An inverse relation was noticed for grain size and cathode rota-

tion speed. This phenomenon can be related to grain refining

mechanism. Large organic molecule (like saccharin) can produce

transient chemical or physical barrier layers to transport of adions

and adatoms on the cathode surface[8]. In rotation speeds higher

than 500 rpm the saccharin adsorption on the cathode surface

maybe was disrupted. These preliminary results on nc nickel was

prepared by rotating cylindrical electrodes and its electrochemical

aspect and mechanism of grain refining deserve further investiga-

tion.

Elements like grain size, internal stress, and porosity [36]affect

the hardness. In general, without considering factors like internal

stress and porosity, the hardness of a polycrystalline metal can be

represented by well-known HallPetch equation.

H= H0+ kd1/2 (1)

where H0 is hardness constant, k a constant, and d grain size.

The results of the microhardness experiments in different saccha-

rin concentration are summarized as a function of grain size in

HallPetch plot ofFig. 7. For comparison the hardness data of other

researches were shown [37,38]. The deviation form HallPetch

equation is not presented in this research, whereas such behavior

is shown byErb [37], Nieh and Wang [38]. The possible explanation

for this discrepancy is such behavior which can be seen in grain

size less than 14 nm in nc nickel. Furthermore, the maximum hard-

ness measured in this investigationwas 620HV forgrain size 14 nm,

which is slightly smaller (about 20 HV) than other results. The dif-

ference can be related to the existence of internal stress or micro

porosity, both of them affect hardness[36].

The HallPetch plot of hardness versus reciprocal square rootof grain size, were calculated for different cathode rotation speed,

is shown inFig. 8.Clearly, the microhardness of nc nickel deposits

was prepared by using rotating electrodes satisfied the HallPetch

equation. But in the stationary cathode condition hardness did not

obey the HallPetch equation. Therefore, in addition to grain size,

defects in the coating affect the microhardness in stationary cath-

ode condition. From electrochemical aspect, the low rotation speed

should indicate that the metal deposition being examined is under

metal ion transport control[39].Therefore, reduction of hydrogen

ion is possible in stationary cathode condition in nickel deposi-

tion. Hydrogen evolution makes defects in the nickel coating and

decrease microhardness in low rotation speed. Furthermore, gas

bubbles on the stationary cathode during electrodeposition were

observed that could locally disrupt saccharin adsorption, so grainsize distribution can be wider in this condition. Totally, wider grain

size distribution and defect can deleteriously influence the hard-

ness of deposit.

The microhardness of nc nickel versus current density at

500rpmand5gl1 saccharinconcentration,as the bestliner trend-

line is shown inFig. 9.Clearly, the deleterious effect of increasing

current density on microhardness is proved. The microhardness

decrease for this coating can be explained as a result of blisters

which were shown in Fig. 1c. Such behavior was reported for nickel

deposition[40].

Fig. 10 exhibits the current efficiency of nickel deposit as a func-

tion of saccharin concentration at 2 A dm2. The current efficiency

for additive-free solution has been determined 95% which is con-

sistent with Brugger [23]. The decrease in current efficiency ispresented by increase of saccharin concentration, and the mini-

mum current efficiency is 87% at 5 g l1 saccharine concentration.

A decrease in current efficiencywas reported fornc andamorphous

NiP electrodeposition by McMahan and Erb and it was related

to the adsorbed hydrogen in deposits [41]. Saccharin addition to

Watts bath increase the cathodic overpotential [23] and it augment

the possibility of phenomena like hydrogen evolution and hydro-

gen adsorbtion. In addition, the reduction of unsaturated bands in

saccharin was reported in nickel deposition [42]. Therefore, by sac-

charin addition in the Watts solution, the total current density is

the sum of the current densities for nickel deposition, hydrogen

evolution, hydrogen adsorbtion, and additive reduction. pH rise

in the bath (at higher saccharin concentration) is a reason that is

consistent with the decrease of efficiency.


5/6

E. Moti et al. / Materials Chemistry and Physics 111 (2008) 469474 473

Fig. 5. Scanningtransmissionelectron micrographs of nc-Ni, electrodeposited withbath containing5 g l1 saccharin, 2A dm2, 500rpm including(a andc) bright-fieldview

in the plane of the foil and (b) dark-field image. (d) Relative grain distribution.

Fig. 6. Effect of cathode rotationspeed on microhardness(--) and grainsize(--).

Fig. 7. HallPetch plot of hardness (HV) vs. reciprocal square-root grain size (d1/2)

fornc-Ni (() thisresearch),compared withdata fromliteratures (() T.G.Nieh) and

(() U. Erb)[36,37].

Fig. 8. HallPetch plot of hardness (HV) vs. reciprocal square-root grain size (d1/2)

for nc-Ni. Results from (--) rotating electrodes and (--) stationary cathode.

Fig. 9. Effect of current density on microhardness.


6/6


Fig.10. Effect of saccharinconcentration on current efficiency(2 A dm2, 500rpm).

4. Conclusions

Nanocrystalline nickel was electrodeposited from a watts bath

with rotating cylindrical electrode. Mirror-like nc nickel with-

out blisters and micro pits was electrodeposited at 2 A dm2,500rpm, and 5g l1 saccharin concentration. Saccharin con-

centration increase changed orientation and refined the grain

size to 14 nm. As a result of better saccharin and hydrogen

adsorption, cathode rotation reinforced the (1 1 1) peak relative

to (1 0 0). We find that nickel exhibits HallPetch strengthen-

ing to grain sizes near 14 nm. The maximum hardness was

620HV and hardness drop was observed with increase of cur-

rent density. The grain size and microhardness were controlled

by changing cathode rotation speed. A decrease in current

efficiency was observed as a result of increase saccharin concen-

tration.

Acknowledgements

The authors wish toextend thanks to Shiraz University Research

Council for their financial support through the grant number

84-GR-ENG-8. The valuable help of the laboratories staff of the

Material Science and Engineering Department in Shiraz Univer-

sity is highly appreciated. The authors wish to express thanks to

Prof. K. Janghorban for his valuable comments on XRD and TEM

micrographs.

References

[1] A.R. Tholen, Mate r. Sci. Eng. A 168 (1993) 131.[2] S.C. Tjong, Haydn Chen, Mater. Sci. Eng. R 45 (2004) 1.[3] G. Palumbo,F. Gonzalez, K. Tomantschger, U. Erb,K.T. Aust, Plat. Surf. Finish. 90

(2003) 36.[4] M.A. Meyer, A. Mishra, D.J. Benson, Prog. Mater. Sci. 51 (2006) 427.[5] U. Erb, NanoStruchued Matial 6 (1995) 533.[6] A.M. El-Sherik, U. Erb, J. Mater. Sci. 50 (1995) 5743.

[7] U. Erb, A.M. El-Sherik, US Patent #5,353,266 (1994).[8] Kh. Saber, C.C. Koch, P.S. Fedkiw, Mater. Sci. Eng. A 341 (2003) 174.[9] G. Qiao, T. Jing, N. Wang, Y. Gao, X. Zhao, J. Zhou, W. Wang,Electrochim. Acta 51

(2005) 85.[10] K.H. Lee, D. Chang, S.C. Kwon, Electrochim. Acta 50 (2005) 4538.[11] A.M. Alfantazi, U. Erb, J. Mater. Lett. 15 (1994) 1361.[12] C.B. Wan, D.L. Wang, W.X. Chen, Y.Y. Wang, Wear 253 (2002) 563.[13] A.F. Zimmerman, G. Palumbo, K.T. Aust, U. Erb, Mater. Sci. Eng. A 328 (2002)

137.[14] C.A. Schuh, T.G. Nieh, T. Yamasaki, Scripta Materialia 46 (2006) 735.[15] Ning Wang, Zhirui Wang, K.T. Aust, U. Erb, Mater. Sci. Eng. A 237 (1997) 150.[16] D.H. Jeong, F. Gonzalez, G. Palumbo, K.T. Aust, U. Erb, Scripta Mater. 44 (2001)

493.[17] A. Robertson, U. Erb, G. Palombo, Nanostruct. Mater. 12 (1999) 1035.[18] R. Mishra, R. Balasubramaniam, Corros. Sci. 46 (2004) 3019.[19] T. Hanlon, Y.-N. Kwon, S. Suresh, Scripta Materialia 49 (2003) 675.[20] R. Mishra, B. Basu, R. Balasubramanian, Mater. Sci. Eng. A 373 (2004) 370.[21] U. Erb, A.M. El-Sherik, C.K.S. Cheung, M. Aus, US Patent No. 5,433,797 (1995).[22] A. CZIRAKI, B. Fogarassy, I. Gerocs, E. toth- Kadar, I. Bakanyi, J. Mater. Sci. 29

(1994) 4771.[23] Robert Brugger, Nickel Plating, Clare OMolesey LTD, 1970, p. 30.[24] M. Paunovic, M. Schlesinger,Fundamentalsof Electrochemical Deposition,Elec-

trochemicalSocietySeries,JohnWileyand SonsInc.,NewYork,1998,pp. 1525.[25] D. Landolt, A. Marlot, Surf. Coat. Technol. 169170 (2003) 8.[26] Leonid V. Azaroff, Elements of X-ray Crystallography, McGraw-Hill (1968) p.

546.[27] U.S. Mohanty, B.C. Tripathy, P. Singh, S.C. Das, Miner. Eng. 15 (2002) 531.[28] Modechay Schlezinger, Milan Punovic, Rolf Weil, in: Modechay Schlezinger,

Milan Punovic (Eds.), Modern Electroplating, John Wiley and Sons Inc., NewYork, 2000, p. 24.

[29] J.K. Denis, J.J. Fuggle, Electroplat. Metal. Fin. 20 (1967) 370.[30] David A. Dudek, Peter S. Fedkiw, J. Electroanal. Chem. 474 (1999) 31.[31] N.S. Qu, D. Zhu, K.C. Chan, W.N. Lei, Surf. Coat. Technol. 168 (2003) 123.[32] Liping Wang, Yan Gao, Qunji Xue, Huiwen Liu, Tao Xu, Mater. Sci. Eng. A 12

(2004) 313.[33] H. Li, F. Czerwinski, A. Szpunar, Nanostruct. Mater. 9 (1997) 673.[34] H. Fischer, Electrodepo s. Surf. Treat. 1 (1972/1973) 319.[35] B. Bozzini, Mater. Chem. Phys. 66 (2000) 278.

[36] J.K. Dennis, T.E. Such, Nickel and Chromium Plating, Butterworth and Co Ltd.,New York, 1986, p. 65.

[37] U. Erb, Nanostruct. Mater. 6 (1995) 533.[38] T.G. Nieh, J.G. Wang, Intermetallics 13 (2005) 377.[39] Colin J.Clarke,GregoryJ. Browning,Scott W.Donne, Electrochim.Acta51(2006)

5773.[40] G. Devaraj, S. Guruviah, Plat. Surf. Fin. 6 (1996) 62.[41] G. McMahan, U. Erb, J. Mater. Sci. Lett. 8 (1998) 865.[42] J. Macheras, D. Vouros, C. Kollia, N. Spyrellis, Trans. Inst. Metal Finishing 74

(1996) 55.

8. electrodeposition of nanocrystalline nickel by using rotating cylindrical electrodes

Documents