MICROSTRUCTURAL EVALUATION OF NANOCRYSTALLINE COBALT-IRON-NICKEL THIN FILMS ELECTRODEPOSITED FROM CITRATE-FREE AND CITRATE-ADDED BATHS

2012 ◽  
Vol 05 ◽  
pp. 712-719
Author(s):  
SAEED MEHRIZI ◽  
M. HYDARZADEH SOHI ◽  
S. A. SEYYED EBRAHIMI
Keyword(s):  
Thin Films ◽  
Sodium Citrate ◽  
Cobalt Content ◽  
Film Composition ◽  
Nickel Thin Films ◽  
Morphological Studies ◽  
Cobalt Iron ◽  
Microstructural Evaluation ◽  
Iron Nickel ◽  
Scherrer Formula

The microstructures of nanocrystalline CoFeNi thin films in direct current electrodeposition, under various processing conditions, have comparatively been investigated. Morphological studies by SEM showed that CoFeNi films plated from the sodium citrate-added baths were more uniform and denser than those deposited from the conventional citrate-free baths. Energy dispersive spectroscopy (EDS) showed the anomalous behaviors in electrodeposition of CoFeNi films from both citrate-added and citrate-free baths. It was also noticed that addition of 10g/L sodium citrate in the bath strongly decreases the iron content and increases nickel contents of the deposit. Addition of citrate up to 50g/L in the bath has reverse effect on the film composition. Further addition of sodium citrate appears to have no or little effect on the film composition. Addition of sodium citrate to the bath has no significant affect on the cobalt content of the deposit. XRD analyses showed that all CoFeNi films were nanocrystalline and their average grain sizes, estimated by Scherrer formula, were below 80nm. It was also noticed that FCC and BCC phases could be co-deposited in electroplated CoFeNi films by controlling the bath composition and/or the plating conditions.

EFFECTS OF SODIUM CITRATE AND CURRENT DENSITY ON ELECTROPLATED NANOCRYSTALLINE COBALT-IRON THIN FILMS

2012 ◽  
Vol 05 ◽  
pp. 696-703 ◽  
Author(s):  
BEHTAM ADELI ◽  
MAHMOUD HYDARZADEH SOHI ◽  
SAEED MEHRIZI
Keyword(s):  
Thin Films ◽  
Current Density ◽  
Iron Content ◽  
Sodium Citrate ◽  
Cobalt Content ◽  
Limiting Current ◽  
Lattice Constants ◽  
Average Grain Size ◽  
Scherrer Formula ◽  
Deposited Films

Effects of sodium citrate dosage and current density on composition and phase structure of nanocrystalline CoFe thin films were systematically studied. Energy dispersive spectroscopy (EDS) showed when sodium citrate dosage in the bath was less than 10 g/L, with increasing citrate in the bath, iron content in the deposited films remarkably decreased. However, sodium citrate dosage more than 20 g/L had no effect on composition of the deposited films. In low current densities, cobalt content decreases and iron content increases, as the current density increases. The current density of 15 ma/cm2 could be considered as alloy limiting current density. The XRD analyses showed that only BCC and/or FCC formed in the deposited films and average grain size, estimated by Scherrer formula, were below 55 nm. The results indicated that phase formation in the electrodeposition of CoFe deviated from equilibrium conditions and was controlled by kinetic conditions. The lattice constants for BCC and FCC phases in CoFe films were close to those of BCC iron and FCC cobalt, respectively.

Synthesis, Characterization and Hall Effect Measurements of Nanocrystalline ZnO Thin Films

2012 ◽  
Vol 510-511 ◽  
pp. 186-193 ◽  
Author(s):  
Ashari Maqsood ◽  
M. Islam ◽  
M. Ikram ◽  
S. Salam ◽  
S. Ameer
Keyword(s):  
Thin Films ◽  
Hall Effect ◽  
Sol Gel ◽  
Visible Region ◽  
Zno Thin Films ◽  
Zno Films ◽  
Morphological Studies ◽  
Hall Effect Measurements ◽  
Scherrer Formula

ZnO thin films were prepared by sol-gel method. Prepared thin films were then characterized by SEM, XRD, EDX and Hall effect measurements. SEM confirmed the morphological studies of ZnO thin films. Crystallite size is calculated using the Scherrer formula. Crystallite and grain sizes are obtained through XRD and SEM. EDS analysis confirms mass percentage of ZnO deposited. Decreasing trend of magneto resistance with temperature is observed. The optical transmission spectra of the solgel deposited ZnO thin films showed high transmittance (>70%) in the visible region and indicates that the transmittance of ZnO films gradually decreased as the thickness increased. Decreasing trend of resistivity and sheet resistance with thickness are also observed. The IV characterization of ZnO thin films under influence of UV and dark conditions are reported. The dc electrical resistivity data follow the hoping model.

Perpendicular Anisotropy of Evaporated Magnetic Iron-Nickel and Cobalt-Nickel Thin Films

1966 ◽  
Vol 21 (10) ◽  
pp. 1914-1921 ◽  
Author(s):  
Tosiaki Koikeda ◽  
Shozo Fujiwara ◽  
Sōshin Chikazumi
Keyword(s):  
Thin Films ◽  
Perpendicular Anisotropy ◽  
Nickel Thin Films ◽  
Cobalt Nickel ◽  
Iron Nickel

The study of interfacial reactions of nickel thin films on GaAs

1983 ◽  
Vol 41 ◽  
pp. 156-157
Author(s):  
L.J. Chen ◽  
Y.F. Hsieh
Keyword(s):  
Thin Films ◽  
Integrated Circuits ◽  
Interfacial Reactions ◽  
Metal Contacts ◽  
Nickel Thin Films ◽  
Thin Foils ◽  
The Status ◽  
Si Doped ◽  
Electron Microscopes

One measure of the maturity of a device technology is the ease and reliability of applying contact metallurgy. Compared to metal contact of silicon, the status of GaAs metallization is still at its primitive stage. With the advent of GaAs MESFET and integrated circuits, very stringent requirements were placed on their metal contacts. During the past few years, extensive researches have been conducted in the area of Au-Ge-Ni in order to lower contact resistances and improve uniformity. In this paper, we report the results of TEM study of interfacial reactions between Ni and GaAs as part of the attempt to understand the role of nickel in Au-Ge-Ni contact of GaAs.N-type, Si-doped, (001) oriented GaAs wafers, 15 mil in thickness, were grown by gradient-freeze method. Nickel thin films, 300Å in thickness, were e-gun deposited on GaAs wafers. The samples were then annealed in dry N2 in a 3-zone diffusion furnace at temperatures 200°C - 600°C for 5-180 minutes. Thin foils for TEM examinations were prepared by chemical polishing from the GaA.s side. TEM investigations were performed with JE0L- 100B and JE0L-200CX electron microscopes.

Analysis of electroless nickel thin films

1991 ◽  
Vol 49 ◽  
pp. 510-511 ◽  
Author(s):  
C. W. Price ◽  
E. F. Lindsey
Keyword(s):  
Thin Films ◽  
Inertial Confinement Fusion ◽  
Electroless Nickel ◽  
Inertial Confinement ◽  
Plating Bath ◽  
X Ray ◽  
Nickel Thin Films ◽  
Nickel Deposits ◽  
Confinement Fusion ◽  
Thickness Measurements

Thickness measurements of thin films are performed by both energy-dispersive x-ray spectroscopy (EDS) and x-ray fluorescence (XRF). XRF can measure thicker films than EDS, and XRF measurements also have somewhat greater precision than EDS measurements. However, small components with curved or irregular shapes that are used for various applications in the the Inertial Confinement Fusion program at LLNL present geometrical problems that are not conducive to XRF analyses but may have only a minimal effect on EDS analyses. This work describes the development of an EDS technique to measure the thickness of electroless nickel deposits on gold substrates. Although elaborate correction techniques have been developed for thin-film measurements by x-ray analysis, the thickness of electroless nickel films can be dependent on the plating bath used. Therefore, standard calibration curves were established by correlating EDS data with thickness measurements that were obtained by contact profilometry.

PULSED LASER IRRADIATION OF NICKEL THIN FILMS ON SILICON

1983 ◽  
Vol 44 (C5) ◽  
pp. C5-449-C5-454 ◽  
Author(s):  
P. Baeri ◽  
M. G. Grimaldi ◽  
E. Rimini ◽  
G. Celotti
Keyword(s):  
Thin Films ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Nickel Thin Films ◽  
Pulsed Laser Irradiation
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