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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 45661 (57)
- University: Sharif University of Technology, International Campus, Kish Island
- Department: Science and Engineering
- Advisor(s): Dolati, Abolghasem
- Abstract:
- Syntheses of coats including nickel nano-particles by electrodeposition have been
investigated for over 10 years. A method of testing according to surface reply was chosen
to reveal the effect of each pulse parameters (including duty cycle, frequency, average
current density, off time (toff) and on time (ton)) and the effect of saccharin concentration
on electroplating cathode efficiency, nanostructure. Pulse electroplating test of nickel was
composed by 30 tests. Pulse electroplating with relatively high peak current density was
employed and saccharine was added to increase deposition and rate of nickel nucleation on
surface. According to the results of cathode efficiency, optimum condition for
electrodeposition were 89.91%, with 3.9 mA/cm2 current density, frequency 57.5 Hz, duty
cycle 38% and with saccharine concentration 3.8 g/l. Scanning Electron Microscope
(SEM) was used to evaluate nickel nano-particles and their distribution. The nanostructure
morphology of coat revealed that decreasing frequency from 155 Hz to 57Hz lead to
change structure from dendrite to spherical mode. Also, reduction of size of spherical
particles in nanometer range can be attributed to increase of current density from 1
mA/cm2 to 3.9 mA/cm2. AFM microscope was used to evaluate surface roughness. The
results of AFM disclosed that there was lower amount of roughness and porosity of surface
in optimum pulse electroplating condition. The mean peaks distances from mean line
(RSM) and mean distances of the highest and lowest peak (Ra) were 6.97 and 5.5 nm,
respectively. X-ray diffraction (XRD) revealed that the preferable planes for developing
nano-particles are (200) and (220). Intensity of peak relating to (200) was increased by
increasing current density. In addition, coat led from watt bath with more saccharine
concentration made increase in peak intensity related to planes (220) - Keywords:
- Nanoparticles ; Pulse Plating ; Morphology ; Electrochemical Deposition ; Nickel ; X-Ray Photoelectron Spectroscopy (XPS)
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