Fabrication of CoFe/BaFe12O19 Magnetic Nanocomposite Thin Films by Electrodeposition

2013 ◽  
Vol 829 ◽  
pp. 332-336
Author(s):  
Soheila Kharratian Khameneh ◽  
M. Heydarzadeh Sohi ◽  
Abolghasem Ataie ◽  
Saeed Mehrizi

A study of the incorporation of barium hexaferrite nanoparticles into a CoFe matrix by means of electrodeposition over brass substrates has been performed. Barium hexaferrite nanoparticles were prepared by co-precipitation route using solution of iron and barium nitrates with a Fe3+/Ba2+molar ratio of 8, by addition of NaOH with a OH-/NO3- molar ratio of 2. X-ray diffraction (XRD) results indicated that in a sample synthesized from aqueous solution and annealed at 900 °C for 1 hour, BaFe12O19 was the dominant phase. Field emission scanning electron microscopy (FE-SEM) showed plate-like particles of barium hexaferrite by mean diameter of 300 nm and thickness of 45 nm. CoFe-BaFe12O19 nanocomposite thin films were then electrodeposited froma Co-Fe bath containing the barium hexaferrite particles obtained in the first stage of this work. Finally, FE-SEM equipped with energy dispersive spectroscopy (EDS) analyzer and XRD analysis was applied on the deposited films, to confirm presence of the nanoparticles in the film. The average crystallite size of the deposits was around 30 nm. It was also noticed that increasing the concentration of the particles in the electroplating bath, caused a rise in the BaFe12O19 content of the deposits but had no significant effect on the composition of the CoFe matrix.

2019 ◽  
Vol 37 (1) ◽  
pp. 33-38 ◽  
Author(s):  
K.K. Pathak ◽  
Mimi Akash Pateria ◽  
Kusumanjali Deshmukh ◽  
Piyush Jha

AbstractPresent paper reports optical and electrical properties of samarium doped CdSe nanocrystalline thin film which was grown on a glass substrate by chemical bath deposition method (CBD). X-ray diffraction (XRD) analysis revealed that the deposited films were nanocrystalline with sphalerite cubic structure. The average crystallite size calculated from FWHM of XRD peaks was found to be 10.11 nm. The bandgap of the Sm doped CdSe nanocrystalline thin films was calculated to be 1.91 eV to 2.22 eV. The optical absorption edge of undoped (pure) and Sm doped CdSe films was obtained between 650 nm to 640 nm showing blue shift as compared to bulk CdSe. Sm doping further enhanced the photoconductivity of these films. The I-V characteristic confirmed the suitability of prepared films for photosensor applications.


2015 ◽  
Vol 9 (3) ◽  
pp. 2461-2469
Author(s):  
S. R. Gosavi ◽  
K. B. Chaudhari

CdS thin films were deposited on glass substrates by using successive ionic layer adsorption and reaction (SILAR) method at room temperature. The effect of SILAR growth cycles on structural, morphological, optical and electrical properties of the films has been studied.  The thickness of the deposited film is measured by employing weight difference method. The X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) studies showed that all the films exhibit polycrystalline nature and are covered well with glass substrates. The values of average crystallite size were found to be 53 nm, 58 nm, 63 nm and 71 nm corresponding to the thin films deposited with 30, 40, 50 and 60 SILAR growth cycles respectively. From the UV–VIS spectra of the deposited thin films, it was seen that both the absorption properties and energy bandgap of the films changes with increasing number of SILAR growth cycles. A decrease of electrical resistivity has been observed with increasing SILAR growth cycle. 


1990 ◽  
Vol 191 ◽  
Author(s):  
Michael E. Geusic ◽  
Alan F. Stewart ◽  
Larry R. Pederson ◽  
William J. Weber ◽  
Kenneth R. Marken ◽  
...  

ABSTRACTExcimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa2Cu3O7−x thin films on (100)-SrTiO3 and (100)-LaAlO3 substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa2Cu3O7−x target at a laser energy density of 2–3 J/cm2. Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures (Tc, midpoint) of 88 and 87K with 2K (90–10%) transition widths for SrTiO3 and LaAlO3, respectively. Transport critical current densities (Jc) measured at 77K were 2 × 106 and 1 × 106 A/cm2 in zero field for SrTiO3 and LaAlO3, respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface.


MRS Advances ◽  
2016 ◽  
Vol 1 (39) ◽  
pp. 2711-2716 ◽  
Author(s):  
V. Vasilyev ◽  
J. Cetnar ◽  
B. Claflin ◽  
G. Grzybowski ◽  
K. Leedy ◽  
...  

ABSTRACTAlN thin film structures have many useful and practical piezoelectric and pyroelectric properties. The potential enhancement of the AlN piezo- and pyroelectric constants allows it to compete with more commonly used materials. For example, combination of AlN with ScN leads to new structural, electronic, and mechanical characteristics, which have been reported to substantially enhance the piezoelectric coefficients in solid-solution AlN-ScN compounds, compared to a pure AlN-phase material.In our work, we demonstrate that an analogous alloying approach results in considerable enhancement of the pyroelectric properties of AlN - ScN composites. Thin films of ScN, AlN and Al1-x ScxN (x = 0 – 1.0) were deposited on silicon (004) substrates using dual reactive sputtering in Ar/N2 atmosphere from Sc and Al targets. The deposited films were studied and compared using x-ray diffraction, XPS, SEM, and pyroelectric characterization. An up to 25% enhancement was observed in the pyroelectric coefficient (Pc = 0.9 µC /m2K) for Sc1-xAlxN thin films structures in comparison to pure AlN thin films (Pc = 0.71 µC/m2K). The obtained results suggest that Al1-x ScxN films could be a promising novel pyroelectric material and might be suitable for use in uncooled IR detectors.


2012 ◽  
Vol 60 (1) ◽  
pp. 137-140 ◽  
Author(s):  
RI Chowdhury ◽  
MS Islam ◽  
F Sabeth ◽  
G Mustafa ◽  
SFU Farhad ◽  
...  

Cadmium selenide (CdSe) thin films have been deposited on glass/conducting glass substrates using low-cost electrodeposition method. X-ray diffraction (XRD) technique has been used to identify the phases present in the deposited films and observed that the deposited films are mainly consisting of CdSe phases. The photoelectrochemical (PEC) cell measurements indicate that the CdSe films are n-type in electrical conduction, and optical absorption measurements show that the bandgap for as-deposited film is estimated to be 2.1 eV. Upon heat treatment at 723 K for 30 min in air the band gap of CdSe film is decreased to 1.8 eV. The surface morphology of the deposited films has been characterized using scanning electron microscopy (SEM) and observed that very homogeneous and uniform CdSe film is grown onto FTO/glass substrate. The aim of this work is to use n-type CdSe window materials in CdTe based solar cell structures. The results will be presented in this paper in the light of observed data.DOI: http://dx.doi.org/10.3329/dujs.v60i1.10352  Dhaka Univ. J. Sci. 60(1): 137-140 2012 (January)


2002 ◽  
Vol 721 ◽  
Author(s):  
M. L. Yan ◽  
N. Powers ◽  
D. J. Sellmyer

AbstractWe report the non-epitaxial growth of highly textured (001) CoPt:B2O3 nanocomposite thin films that are deposited directly on thermally-oxidized Si wafers. Multilayers of Co/Pt/Co/B2O3 are deposited followed by appropriate thermal processing. The as-deposited films are disordered fcc CoPt phase, and magnetically soft. After annealing, an (001) orientation of CoPt-ordered grains is developed. The texture development is dependent both on the total film thickness and the annealing process. Nearly perfect (001) texture can be obtained in films with thinner initial layer thicknesses. Strong perpendicular anisotropy is shown to be related to this (001) texture.


2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.


2021 ◽  
Author(s):  
Raji P ◽  
K Balachandra Kumar

Abstract Ti - doped ZnO (TixZn1-xO x= 0.00, 0.05, 0.10, 0.15) nanoparticles have been synthesized through co - precipitation approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), UV-Visible spectroscopy, and Vibrating Sample Magnetometer (VSM) have been used to characterize the samples. X-Ray Diffraction (XRD) analysis manifested the hexagonal wurtzite structure. The crystallite size decreased from 37 ​nm to 29 ​nm as dopant concentration is increased. Fourier transform infrared analysis showed the absorption bands of ZnO, with few within the intensities. SEM investigation showed the irregular shape and agglomeration of the particles. Ti, Zn, and O composition were determined from EDX analysis and confirmed the purity of the samples.PL spectra showed a near band edge emission and visible emission.Vibrating sample magnetometer (VSM) demonstrated pure and doped samples exhibited ferromagnetism behavior at room temperature.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tizazu Abza ◽  
Dereje Gelanu Dadi ◽  
Fekadu Gashaw Hone ◽  
Tesfaye Chebelew Meharu ◽  
Gebremeskel Tekle ◽  
...  

Cobalt sulfide thin films were synthesized from acidic chemical baths by varying the deposition time. The powder X-ray diffraction studies indicated that there are hexagonal CoS, face-centered cubic Co3S4, and cubic Co9S8 phases of cobalt sulfide. The crystallite size of the hexagonal CoS phase decreased from 52.8 nm to 22.5 nm and that of the cubic Co9S8 phase increased from 11 nm to 60 nm as the deposition time increased from 2 hrs to 3.5 hrs. The scanning electron microscopic images revealed crack and pinhole free thin films with uniform and smooth background and few large polygonal grains on the surface. The band gap of the cobalt sulfide thin films decreased from 1.75 eV to 1.3 eV as the deposition time increased from 2 hrs to 3.5 hrs. The photoluminescence (PL) spectra of the films confirmed the emission of ultraviolet, violet, and blue lights. The intense PL emission of violet light at 384 nm had red shifted with increasing deposition time that could be resulted from the increase in the average crystallite size. The FTIR spectra of the films indicated the presence of OH, C-O-H, C-O, double sulfide, and Co-S groups. As the deposition time increased, the electrical resistivity of the cobalt sulfide thin films decreased due to the increase in both the crystallite size and the films’ thickness.


2008 ◽  
Vol 55-57 ◽  
pp. 881-884 ◽  
Author(s):  
Thitinai Gaewdang ◽  
N. Wongcharoen ◽  
P. Siribuddhaiwon ◽  
N. Promros

CdTe thin films with different substrate temperatures have been deposited by thermal evaporation method on glass substrate in vacuum chamber having low pressure about 3.0x10-5 mbar. According to XRD analysis, CdTe thin films are polycrystalline belonging to cubic structure with preferential orientation of (111) plane. The strongest peak intensity of XRD is observed in the film prepared with substrate temperature of 150°C. Band gap and band tail values of the as-deposited films were evaluated from the optical transmission spectra. The lowest dark sheet resistance value was obtained from the film prepared with substrate temperature of 150°C as well. Regarding to our experimental results, it may be indicated that the 150°C substrate temperature is the most suitable condition in preparing CdTe thin films for solar cell applications.


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