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

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.

2012 ◽  
Vol 05 ◽  
pp. 712-719
Author(s):  
SAEED MEHRIZI ◽  
M. HYDARZADEH SOHI ◽  
S. A. SEYYED EBRAHIMI

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.


2022 ◽  
Vol 1048 ◽  
pp. 189-197
Author(s):  
Tippasani Srinivasa Reddy ◽  
M.C. Santhosh Kumar

In this study report the structural and optical properties of Copper Tin Sulfide (Cu2SnS3) thin films on indium tin oxide (ITO) substrate using co-evaporation technique. High purity of copper, tin and sulfur were taken as source materials to deposit Cu2SnS3 (CTS) thin films at different substrate temperatures (200-350 °C). Further, the effect of different substrate temperature on the crystallographic, morphological and optical properties of CTS thin films was investigated. The deposited CTS thin films shows tetragonal phase with preferential orientation along (112) plane confirmed by X-ray diffraction. Micro-Raman studies reveled the formation of CTS thin films. The surface morphology, average grain size and rms values of the deposited films are examined by Scanning electron spectroscopy (SEM) and Atomic Force Microscopy (AFM). The Energy dispersive spectroscopy (EDS) shows the presence of copper, tin and sulfur with a nearly stoichiometric ratio. The optical band gap (1.76-1.63 eV) and absorption coefficient (~105 cm-1) of the films was calculated by using UV-Vis-NIR spectroscopy. The values of refractive index, extinction coefficient and permittivity of the deposited films were calculated from the optical transmittance data.


2013 ◽  
Vol 665 ◽  
pp. 93-100 ◽  
Author(s):  
T.H. Patel

SnS (tin sulphide) is of interest for use as an absorber layer and the wider energy band gap phases e.g. SnS2, Sn2S3and Sn/S/O alloys of interest as Cd-free buffer layers for use in thin film solar cells. Thin films of tin sulphide have been deposited using CBD at three different bath temperatures (27, 35 and 45 °C) onto microscope glass substrates. The X ray diffraction (XRD) analysis of the deposited films reveled that all films has orthorhombic SnS phase as dominant one with preferred orientations along (111) direction. The temperature influence on the crystalline nature and the presence of other phases of SnS has been observed. The average grain size in the films determined from Scherers formula as well as from Williamson-Hall-plot method agrees well with each other. Energy dispersive X-ray (EDAX) analysis used to determine the film composition suggested that films are almost stoichiometric. The scanning electron microscopy (SEM) reveals that deposited films are pinhole free and consists of uniformly distributed spherical grains. The optical analysis in the 200-1200 nm range suggests that direct allowed transitions are dominant in the absorption process in the films with variation in the band gap (~1.79 to ~2.05 eV) due to variation in deposition temperature.


2002 ◽  
Vol 748 ◽  
Author(s):  
Suprem R. Das ◽  
Rasmi R. Das ◽  
P. Bhattacharya ◽  
Ram S. Katiyar

ABSTRACTPulsed laser deposition technique was used to fabricate Ba0.5Sr0.5TiO 3 (BST) thin-films on Pt/TiO 2/SiO2/Si substrates. The influence of thin interfacial layers of Ta2O5, TiO2, and ZrO2, on the structural and electrical properties of BST thin films was investigated. Insertion of interfacial layers does not affect the perovskite phase formation of BST thin films. Buffer layers helped to make uniform distribution of grains and resulted in a relative increase in the average grain size. The dielectric tunability of BST thin films was reduced with the presence of buffer layers. A BST thin film having a dielectric permitivity of 470 reduced to 337, 235 and 233 in the presence of Ta2O5, TiO2, and ZrO2 layers, respectively. The reduction of the relative dielectric permittivity of BST films with the insertion of interfacial layers was explained in terms of a series capacitance effect, due to the low dielectric constant of interfacial layers. The TiO2 layer did not show any appreciable change in the leakage current density. Deposition of thin Ta2O5 and ZrO2 interfacial layer on top of Pt reduced the leakage current density by an order of magnitude.


2021 ◽  
Vol 03 (03) ◽  
pp. 92-102
Author(s):  
Bilal Y. TAHER ◽  
Ahmad S. AHMAD

CuAlS2 thin films have been prepared on glass substrates by Chemical bath deposition (CBD) technique at a substrate temperature (Ts) 75C, pH value 10.5.The Effect of three different molar concentration (0.05, 0.025, 0.1), (0.075, 0.0375, 0.15), and (0.1, 0.05, 0.2) M of precursors of (CuSO4.5H2O, Al2(SO4)3.16H2O, and (NH2)2CS), respectively on the structural, optical and electrical properties of deposit thin films was studied. The X-ray diffraction (XRD) patterns showed that the films have an amorphous structure with simple enhancement in the structure of the films with the higher molar concentration. Field emission scanning electron microscopy (FESEM) analysis of thin films showed that the deposited films were a good surface morphology, homogenous and uniform spherical nanoparticles over the substrate surface with very little agglomerated particles with average grain size in the range (45 to 72 nm) increase with increasing molar concentration of precursors. Atomic force microscopy (AFM) showed the topography of deposited films has nanoparticles with structures like conical and lobes shape, with the average grain sizes, root mean square (rms) roughness, and surface roughness increase with increasing molar concentration of precursors. The optical analysis by UV-Vis Spectrophotometer showed high absorption in the ultraviolet region, with absorption edge and direct energy gaps (3.5 to 4eV) variedat different molar concentrations of precursors. The electrical results from Hall effect measurements showed that the values of resistivity, conductivity, mobility, and carrier concentration were varied in range (0.046 to 0.594ohm.cm), (1.86 to 21.7(ohm.cm)-1), (301to 1510 cm2/V.S), and (3.29×1016 to 1.46×1017 cm-3), respectively .Also,n-type conductivity was investigated for all prepared film sat different molar concentration of precursors. The obtained results of the prepared CuAlS2 thin films can be suitable in many optoelectronics applications.


2007 ◽  
Vol 998 ◽  
Author(s):  
Thais Cavalheri dos Santos ◽  
Marcelo Mulato

ABSTRACTNife alloys are potential candidates for the development of planar fluxgate magnetic microsensors. In this work, electrodeposition was used to produce NiFe thin films on top of copper substrates. When using this technique the variation of the electric potential, and thus the current density, alters the final stoichiometry of the deposited films, while the final thickness is determined by the total deposition time. We used current densities varying from 4.0 mA/cm2 to 28 mA/cm2, with steps of 4.0 mA/cm2. For each current density, total deposition times of 10, 20, 30 and 40 minutes were used. The morphology was characterized using scanning electron microscopy, structure was characterized using X-ray diffraction experiments, and the composition of the films were determined using energy dispersive spectroscopy. The magnetic properties were investigated evaluating the materials hysteresis cycle. The materials were optimized aiming for lowest coercivity values, and the final result was about 0.215 kA/m.


2014 ◽  
Vol 602-603 ◽  
pp. 800-803
Author(s):  
Min Chang Kuan ◽  
Fann Wei Yang ◽  
Chien Min Cheng ◽  
Kai Huang Chen ◽  
Jian Tz Lee

Lead-free potassium sodium niobate ceramic thin films were synthesized using rf magnetron sputtering technology for MFIS structures. The optimal sputtering parameters of the as-deposited KNN thin films for depositing times of 1h were obtained. Regarding the measured physical properties, the micro-structure and thickness of as-deposited KNN thin films for different oxygen concentration were obtained and compared by XRD patterns and SEM images. The surface roughness of KNN thin film was also observed by AFM morphology. The average grain size and root mean square roughness were 250 and 7.04 nm, respectively. For KNN thin films in the MFIS structure, the capacitance and leakage current density were 280 pF and 10-8A/cm2, respectively. We investigated that the leakage current density and the memory window increased, the capacitance critically increased as the oxygen concentration increased from 0 to 40%. However, the excess oxygen concentration process was decreased the electrical and physical of as-deposited KNN thin film. The effect of oxygen concentration on the physical and electrical characteristics of KNN thin films was investigated and determined.


2017 ◽  
Vol 751 ◽  
pp. 84-87
Author(s):  
Amonrat Khambun ◽  
Adisorn Buranawong ◽  
Nirun Witit-Anun

Nanocrystalline CrAlN thin films were deposited on silicon substrates by reactive DC magnetron co-sputtering technique. The effect of deposition time on crystal structure, chemical composition, thickness, microstructure and hardness of the thin films were characterized by XRD, EDS, AFM and FE-SEM and Nanoindentation, respectively. The as-deposited films were formed as a (Cr,Al)N solid solution with (111), (200) and (220) plane. The lattice constants were in range of 3.9916 - 4.0455 Å. The as-deposited films exhibited a nanostructure with a crystallite size in range of 15-35 nm. The thickness and roughness increased from 197 nm to 998 nm and 1.6 nm to 8.1 nm, respectively, with increasing the deposition time. The chemical composition of the films varied with the deposition time. The cross section analysis by FE-SEM showed columnar structure and dense morphology. The film hardness decreased from 39 GPa to 25 GPa with increasing the deposition time and crystallite size.


2016 ◽  
Vol 675-676 ◽  
pp. 181-184 ◽  
Author(s):  
Nirun Witit-Anun ◽  
Amphol Teekhaboot

Titanium chromium nitride (TiCrN) thin films were deposited by reactive DC magnetron co-sputtering. The effect of Ti sputtering current (ITi) on the structure of the TiCrN thin films were investigated. The crystal structure, microstructure, thickness, roughness and elemental composition were characterized by glancing angle X-ray diffraction (GAXRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDS) technique, respectively. The results showed that, all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited films exhibited a nanostructure with a crystallite size of less than 40 nm. The crystal size decreased from 39.9 nm to 33.5 nm, while the lattice constants increased from 4.139 Å to 4.162 Å, with increasing of the Ti sputtering current. The film thickness and roughness were found to increase from 397 nm to 615 nm and 3.7 nm to 6.3 nm, respectively, with increasing of the Ti sputtering current. The composition of the as-deposited films varied with the Ti sputtering current. Cross section analysis by FE-SEM showed compact columnar and dense morphology as a result of increasing the Ti sputtering current.


2020 ◽  
Vol 901 ◽  
pp. 37-42
Author(s):  
Siriwat Alaksanasuwan ◽  
Adisorn Buranawong ◽  
Nirun Witit-Anun

TiCrN thin films have been prepared using a reactive DC magnetron sputtering system from a mosaic target. The effects of sputtering current, in the range of 300 to 700 mA, on the structure of the thin films were investigated. The crystal structure, microstructure, thickness, and composition were characterized by GI-XRD, FE-SEM and EDS technique, respectively. The results revealed that all the as-deposited films were formed as a (Ti,Cr)N solid solution. The as-deposited TiCrN films showed a nanostructure with a crystallite size less than 70 nm. The crystal sizes of all planes were in the range of 22.2 to 69.9 nm. The lattice constants were in the range of 4.149 Å to 4.175 Å. The thickness increases from 1630 nm to 4910 nm with increasing the sputtering current. The elemental composition (Ti Cr and N contents) of the as-deposited films were varied with the sputtering current. Lastly, the all of the thin films in this work showed compact columnar and dense morphology as a resulted of increasing the sputtering current.


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